JOINT DOCUMENTS. lakes Huron and Michigan, for which reason my remarks at this time will be mostly confined to the northerly [No. 11.] portion of the peninsula, or that portion bordering upon Lake Superior. So little is known of the extent of country constituting the Annual Report of the State Geologist. upper peninsula, that it may not be misplaced to make OFFICE OF STATE GEOLOGIST, some reference to its dimensions, though at this time Detroit, February 1, 1841. most of the estimates must be regarded as mere approximations. The most extreme length of the district To the Senate and House of Representatives: is embraced between Point de Tour, of Lake Huron, on In conformity with instructions contained in the act the east, and the mouth of Montreal river, of Lake authorizing a geological survey of the state, I have the Superior, on the west. From Point de Tour, the direction honor to lay before you, an outline of the operations of of the mouth of Montreal river is very nearly north, 80° the department over which I have been placed, together 30’ west, and the direct distance does not vary far from with the general progress towards completion, of the 316 miles. This estimate, it will be perceived, does not whole work. include Drummond’s Island, which, if included, would add some 20 miles to the length as already given. It is a matter of regret to me, that the sufferings and hardships to which I have been exposed in conducting The easterly portion of the peninsula is narrow, and its the field work over the wilderness portions of our state, width, for a distance of 130 miles west from Point de have so far impaired my health, as to render it Tour, varies from 30 to 50 miles; west from this, the impossible for me to enter into so minute details as had peninsula widens rapidly, though its width is exceedingly been anticipated. I regret this the more, since it leaves irregular. I am unable, at this time, to state with very many wide spaces in portions of the present report, much accuracy, the extreme width of the upper which are of much consequence to a proper peninsula, but the area of the whole may be estimated at understanding of the whole. But since the annual very nearly two-thirds that of the lower, or southern reports are intended to refer rather to the progress of the peninsula. work than to its results, and since the whole will be The topography and general features of the upper and embraced in a more perfect form hereafter, this defect is lower peninsulas differ so widely from each other, that, of less importance than it otherwise would be. with the simple exception of a part of the easterly My individual labors, during the past season, have been extremity of the upper peninsula, they scarcely admit of chiefly devoted to surveys connected with the northern a comparison. The wide contrast exhibited by the two slope of the upper peninsula, and to this district, the districts, is wholly dependent upon geological chief observations in this report, will be directed. differences, and these are so strongly marked, that they could not fail to attract the notice of the most superficial observer. UPPER OR NORTHERN PENINSULA. In the last report I had the honor to lay before you, some general references were made to the topography of the General description and Topographical features. southern slope of the upper peninsula, which embraced The published maps of that portion of the state of simply those portions bordering upon lakes Huron and Michigan usually known as the Upper Peninsula, are so Michigan, and extending from Point de Tour to defective, not only in details, but also in general outline, Monominee river. that the task of giving a description of any portion, in Although the rocks of the district extending from Point de such a manner as to render it intelligible to any person Tour to Chocolate river, upon the northerly or Lake who has not actually traveled over it, is exceedingly Superior slope, belong to an older series than those difficult. The extent of these geographical inaccuracies lying south, and are different in composition, the general is much greater than would at first be supposed, for features of the two dis- scarcely a single feature of the interior is given as it actually exists; mere brooks are magnified to rivers, and *I am happy in being able to except from this otherwise universal again, those streams justly deserving the name of rivers, charge of inaccuracy, the coast map of Lake Superior published by the Society for the diffusion of useful knowledge. This map was reduced are either wholly omitted or scarcely noted, while the from the surveys of Capt. Bayfield, R. N., as returned to the British courses of the streams, as laid down, are almost admiralty office, and so far as the British coast is concerned, the map invariably as far from the truth as could be conceived. is minutely correct. The American coast upon tins map is faithfully Nor do the inaccuracies stop here, for even the coast delineated in its general outline, but in minutiae it is frequently maps of the great lakes, by which our upper peninsula is deficient. in part surrounded, are usually so defective as scarcely tricts, nevertheless, bear a close resemblance. Easterly to be recognized, except in their most general outlines.* from Point Iroquois, the country is for the most part flat, I have already, in a previous report, referred in general or but slightly elevated, and the near approach of the terms, to that portion of the upper peninsula bounded by rock to the surface so far prevents the descent of the waters, as to give rise to extensive districts of wet and Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 1 of 59 swaly land. Westerly from Point Iroquois to Chocolate line, making the total width at this point 87 geographical river, the country is more elevated, and has a much miles. The very great irregularities of the coast, with the smaller proportion of wet land. A range of hills, having numerous deep bays and projecting points upon the an elevation varying from 300 to 600 feet above Lake north, together with the irregularities of the ranges of hills Superior, commences a little easterly from Point upon the south, cause so great variations in the width of Iroquois, and stretches very nearly west, or but a few the district, that it is impossible, with the present degrees north of west, until the western escapement information upon this subject, to estimate the width of again appears upon the coast, giving rise to the elevated the district with any great degree of accuracy, hills of which the Pictured rocks and Grand island form a Keweenaw bay, of Lake Superior, stretches 60 miles, part. The outline of this range of hills has the most estimating from the extremity of Keweenaw point, into perfect regularity, being unbroken and uniformly covered this hilly or mountainous country. with a dense growth of timber. South from the range of hilly country alluded to, and West from Chocolate river, to our boundary line at extending to Green bay, the country at first becomes Montreal river, the physical character of the country is more level and finally flat, though with several regular widely different from that of the district before referred to. and unbroken ranges of hills. In topography and general This country is made up of a series of irregular, knobby character, it more nearly resembles that district of ranges of hills, that have a general easterly and westerly country which lies east from Chocolate river. direction, with intervening valleys of flat or gently rolling Of the district of country lying between the hilly country land. These hills not unfrequently rise to a height of from and Green bay, less is known than of any other portion 600 to 900 feet, very near to the immediate coast of of the upper peninsula. The extent of my duties did not Lake Superior, and at a distance of 15 to 20 miles south permit me to extend my examinations very far into it, nor from the coast, portions of some of the ranges rise to a was I enabled to obtain any information as to its general height of 1,200 to 1,300 feet above the level of that lake. character. The ragged and broken outline which this district presents, when viewed in detail, from the lake, contrasts The streams which discharge their waters into Lake in a striking manner, with, that of the country lying east Superior upon its south shore, are invariably short, and from Chocolate river; for, instead of the regular and with very few exceptions, the quantity of water they unbroken range of hills, uniformly covered with a dense discharge is small. This remark, in fact, may apply to the forest, that occur in the latter district, we have a series of whole of the region of country surrounding that lake, for ranges of broken hills, with knobs not unfrequently this immense body of water is completely surrounded by nearly or quite destitute of timber. The escapements of hills that, at no great distance from the lake, fall away these hills are sometimes so abrupt as to render them more or less rapidly. Thus, while many of the streams difficult of ascent. discharging their waters into Lake Michigan, Green bay and the Mississippi river, have their sources near to the The only exception to the general easterly and westerly south shore of Lake Superior, so also, many of those direction of these ranges of hills, occurs in that range streams which discharge their waters northerly into constituting the Porcupine mountains. These mountains Hudson’s bay, have their sources near to the north coast rise somewhat abruptly almost upon the immediate of the lake. The near approach of the summit of the coast of Lake Superior, at a point 37 miles north-easterly ranges of hills surrounding the lake, to the immediate from the mouth of Montreal river, and from this point they coast, leaves the area of country draining into Lake stretch inland, in a direction which, for the first 30 miles, Superior, comparatively small. is very nearly south-south-west, after which their course is more westerly, and in the direction of the sources of The most important of the streams entering Lake the Wisconsin river. The most elevated points of the Superior upon its south shore and within the limits of our Porcupine mountains, near to Lake Superior, attain an state, (commencing near the foot of the lake and altitude of very nearly 950 feet, but several of the knobs, enumerating westwardly,) are the Tequoimenon, Train, at a distance inland, rise from 1,100 to 1,300 feet above Chocolate, Death, Yellow dog, Huron, Portage, Fire the level of the waters of that lake. Steel, Ontonagon, Iron, Presque Isle, Black and Montreal rivers. Besides these, there are innumerable The valleys, before referred to as separating these creeks, which are usually known to voyageurs as rivers, ranges of hills, are uniformly heavily timbered, and by far for this term is applied indiscriminately to all. The waters the largest proportion of this timber is beech and maple. of most of these streams are remarkably transparent and The length of the hilly or mountainous district, estimating pure, with brisk currents and numerous cascades, and in a direct line west from Chocolate river to the boundary they almost invariably contain an abundance of the line on Montreal river, is very nearly one hundred and brook trout, a circumstance which I mention, from the sixty miles, and it does not probably extend, at any point, fact that this fish is scarcely known in the streams of the more than 20 to 25 miles south from this line. Estimating southern peninsula. this hilly district to extend regularly 20 miles south of a The Tequoimenon river, which is the only stream east line drawn from the points before mentioned, the from Chocolate river, that in reality breaks through the greatest width of the district would be opposite range of sandstone hills, before mentioned as extending Keweenaw point, which extends 67 miles north from this Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 2 of 59 westerly from Point Iroquois, has its embouchure about Ontonagon river, which is one of the most important of 18 miles south from White Fish point, and near the foot the rivers discharging its waters into Lake Superior, upon of the lake. The discharge is through loose sands, and its south shore, has its embouchure very nearly fifty-five there is an average of 4 to 4½ feet water over the bar. miles east, or rather north-easterly, from the western Having passed the bar, the water for a distance of 7 to 8 boundary of the state, at the mouth of Montreal river. miles varies from 10 to 15 feet in depth. Ontonagon river has its sources in a very great number of mountain lakes, situated in part upon the south- Some of the sources of this stream approach very nearly easterly spurs of the Porcupine mountains, and in port in to Lake Michigan, being directly at the base of the range the hilly district formed by the easterly and westerly of lime rock hills, referred to in my third annual report. ranges of hills before described; which ranges, upon this The Tequoimenon river, with the exception of a distance portion of the coast, curve very considerably to the of some 4 to 5 miles, while passing through the range of south. Some of the sources of the Ontonagon river sandstone hills before alluded to, is, through its whole approach very near to the sources of the Chippewa river course, a sluggish stream, though at many points having of the Mississippi. The great number of small tributaries a strong, deep current. The character of the river, in its of the Ontonagon, which are simply the outlets of the passage through the range of hills referred to, is totally small lakes referred to, are concentrated into two changed, for it has there numerous chutes and falls, with principally branches that finally unite and form the almost continuous rapids. At one point, the whole body principal river, at a distance of about eighteen miles from of water contained in the stream is precipitated by a the coast of Lake Superior. The smaller tributaries are single leap, from a height of 46 feet, and the effect of this mostly mere torrents, with frequent perpendicular falls, fall is much heightened by the elevated and overhanging and high banks, sometimes, of precipitous rock. The rocks that bound the river upon either side. main stream, from the junction of the two principal branches to within five or six miles of the lake, is rapid Most of the small streams, discharging into Lake and shoal, but below this, the stream is comparatively Superior between the foot of the lake and Chocolate still, and with a good depth of water. The mouth of the river, have their sources to the north of the elevated Ontonagon river is obstructed by a bar of sand, over range of hills mentioned, or minor branches only which there is usually, at low stages, about six feet of descend from those hills. water. Chocolate river, which discharges its waters into Lake The principal rivers west from Ontonagon river and Superior at a point 146 miles very nearly due west from within the limits of our state, have already been stated to the Saut de Ste Marie, is a stream of considerable be Iron, Presque Isle, Black and Montreal rivers. These magnitude, though in consequence of the loose sands at streams are all short, and the amount of water its mouth, it is difficult of entrance at ordinary stages of discharged by each separately is comparatively small. water, even with barges of moderate draught, but when Their waters descend from the elevated mountain region once the bar is passed, the stream is found to be deep, immediately south from the coast, and since the whole and for several miles has a width varying from 80 to 150 streams are concentrated before passing from these feet. elevations, their waters are discharged in body and they This stream will be made a point of reference in the descend with very great rapidity. A greater variety of strictly geological portions of this report, for it winds grand and beautiful scenery than that presented by along near the line of junction of two widely distinct some of these streams in their descent to the lake, taken geological districts; the general features of one being in connexion with the rugged and wild character of the characterized by its ragged and broken hills, while the country, can scarcely be conceived. I was particularly other is not less marked by its generally level or regularly struck with the great variety of picturesque views undulating surface. furnished by Black rive, in its descent from the elevated country on the west side of the Porcupine mountains to Chocolate river takes its name from the dark color of its Lake Superior. The stream was estimated to fall about waters. five hundred feet in a fraction over four miles, and this Those streams which occur between Chocolate river and descent is made up by a constant succession of falls, Keweenaw bay, are, with the exception of Huron river, chutes and rapids, which continue with so little small; though were we to refer to the published maps of interruption that the waters for the whole distance may this district, we would suppose that some of these be said to be constantly white foam. The stream is streams were of very considerable length. But with the bounded upon either side by banks elevated from one exception of Huron river and River Des Morts, I believe hundred to three hundred feet sometimes sloping away they all have their sources, in small lakes lying along the from the stream, somewhat gently, and again rising in bases of the elevated hills already described. These mural precipices of rock, separated from each other by hills rarely recede farther than three to five miles from so short distances as to appear scarcely sufficient to the coast, and the length of the streams, forming the permit the passage of the waters of the river. The most outlets of the lakes referred to, is governed wholly by considerable fall does not exceed fifty feet, and they are these features. usually from ten to thirty feet in height, but their constant succession and variety, add much to its interest.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 3 of 59 Montreal river is a comparatively small stream, made up notwithstanding this, it is of immense value for its of numerous small tributaries, that rise among the fisheries, which are as yet scarcely appreciated. ranges of hills to the south-west and south-east of its Though not within the limits of our state, I will briefly refer mouth. The passage of the river through the range of to the general character of a portion of the country west hills near the lake, gives rise to several very from Pigeon river, on the north coast. That district of considerable water-falls, as also to much ragged and country upon the immediate coast, extending from our wild scenery. Almost directly at the place of national boundary, at Pigeon river, to Fond du Lac, is embouchure into Lake Superior, there is a perpendicular more decidedly and abruptly mountainous than any fall of about 40 feet. This stream, it will be recollected, portion of the south coast of the lake. The hills rise in forms a portion of the boundary between Michigan and broad and somewhat knobby steppes or plateaus, to Wisconsin. heights varying from 400 to 1,200 feet above the lake, By the act admitting Michigan as a state into the and the summits of these hills are usually not farther confederacy, and in which her boundaries are defined, it inland than from 10 to 20 miles. The rocks of the hills does not appear to have been the intention to include are very frequently bare over considerable areas, and within her limits any portion of territory lying upon the the valleys containing arable soil, are few and very north shore of Lake Superior, but in consequence of the narrow. peculiar shape of the coast at that point where the The route of the fur trade to the north-west, via Rainy national boundary line “last touches Lake Superior,” at lakes, Lake of the Woods, and Lake Winnepic, was the mouth of Pigeon river, a direct line to the mouth of formerly wholly carried on by passing over these hills, the Montreal river, if followed literally, would throw within from a point a few miles west from the mouth of Pigeon the state of Michigan several small rocky islands, river. The trail or portage path passes over a low portion together with a few miles of the south cape of Pigeon of the range, and finally falls upon Pigeon river, which is bay, situate upon the north coast. This boundary leaves ascended to its source, from which, by a series of in Wisconsin the whole of the Apostles’ group of islands, portages, the sources of the streams flowing north- near to the south coast, while it includes within Michigan, westerly are reached. The hilly portion of the country, Isle Royale, situate near to the north coast of the lake. though of exceeding interest in a geological point of Isle Royale is little less than an island of rock, rising view, is the most desolate that could be conceived. abruptly from the lowest depth of the lake, in irregular hills, to a height varying from 100 to 450 feet above the GENERAL GEOLOGY OF THE UPPER level of the lake. The island has a length of a fraction PENINSULA. over 45 miles from north-east to south-west, and a breadth varying from 3½ to 8 miles. The most northerly The geology of the upper or northern peninsula of point of the island is very nearly in latitude 48° 12’ 30” Michigan, when compared with that of the southern or north, and the parallel of longitude 89° west from lower peninsula, bears a striking contrast; for while that Greenwich, crosses the island a little east from its of the district last referred to is uniformly regular, with centre. Its nearest approach to the main land is near its rocks which, though rarely exposed to view, are few and north-westerly end, where it is separated from a point of for the most part but little disturbed, over large areas of the north coast, a few miles east from Pigeon river, by a country, the upper peninsula embraces a much greater distance of a fraction less than 13 miles. Isle Royale is number of rocks, distributed over a somewhat smaller separated from Keweenaw point, of the south coast, by district of country, and a portion of which are so much a distance of 44 miles, and the elevated hills of this point disturbed, as to render their delineation exceedingly may be distinctly seen from Isle Royale, when the complex and difficult. atmosphere is clear. The widely different topographical features of the Nearly the whole of the north-westerly side of Isle easterly and westerly portions of the northerly part of the Royale is a continuous, elevated, rocky cliff, which will upper peninsula would lead the most casual observer to scarcely admit of a landing, but the south-easterly side, infer that the geological features of the different districts together with the easterly and westerly ends, are deeply would be equally distinct, and in this he would not be indented with bays, which form secure harbors. The disappointed. north-easterly end is made up of a series of elevated, I have already referred to the rugged and broken rocky spits, with intervening bays. These spits of rock character of the country, extending westerly from continue for a length varying from 10 to 12 miles, with a Chocolate river to our boundary at Montreal river, and width scarcely exceeding half a mile, and altogether, have also attempted to define its general length and they may not inaptly be compared to the hand with the breadth. This district, which is essentially made up of fingers half spread. The bays have a sufficient depth of primary, trap and metamorphic rocks, with intervening water to admit vessels of the largest class to enter nearly sedimentary rocks, usually occupying the valleys and out one third the whole length of the island. boundaries, may be estimated to cover an area equal to Much of Isle Royale is absolutely destitute of soil, and a little more than one-fourth of the whole of the upper the island has a most desolate appearance; but peninsula. To the east and south of this district the

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 4 of 59 rocks are wholly sedimentary, consisting of a series of nearly 25 miles inland. Westerly from Ontonagon river, sandstones, limestones and shales. the range becomes confounded with the northerly portions of the Porcupine mountains; while west from With a view of rendering the local details of the separate these mountains, a portion of what may be considered formations more intelligible, I will first describe, in the same range of rock, has taken a more westerly general terms, the rocks occurring in so much of the course and approaches the coast, until, at the crossing peninsula as has been examined, together with their of the Montreal river, it is but a few miles distant from general extent. This will necessarily involve a repetition Lake Superior. West from the Porcupine mountains, a of a very small portion of the report last made, upon the second range of trap is continued at a distance of from subject of the limestones of the south and east portions fifteen to twenty miles inland. The trap range of of the peninsula, but since the examinations of the past Keweenaw point may be estimated to compose one third year have enabled me to add another member to the the entire width of the point, and the southeasterly limestone group, and to define with more certainty its portions of the range are made up of compact green- outline, this may not be devoid of interest. stone, while those portions to the north-west are 1. Primary Rocks.—The rocks constituting what may be amygdaloid. considered as the true primary group of this region, are The ranges of hills constituting the north-westerly part of chiefly granite, syenite and syenitic granites. The Isle Royale, and extending its whole length, are of members of the group are first seen upon the south similar rocks, and single knobs of well defined trap rock coast of Lake Superior, constituting a rocky point known occasionally occur, in the very midst of the primary as Little Presque isle, a little south-east from Riv. Des region before referred to, upon the south coast; the Morts. These rocks frequently appear upon the coast proofs of the character of which will be shown as we north-westerly, nearly as far as Huron river, and the advance. Huron islands off the mouth of Huron river belong to the same group. West from Huron islands, no rock appears 3. Metamorphic Rocks.—Flanking the primary rocks on upon the coast which, in a strict sense, I should regard the south, is a series of stratified rocks consisting of as primary. The rocks of this group rise upon or near to talcose, mica and clay slates, slaty hornblende rock, and the coast, in irregular and broken ranges of hills, to a quartz rock; the latter rock constituting by far the largest height varying from 300 to 700 feet above the waters of proportion of the whole group. In traversing the country the lake, and these hills or ranges of hills are continued south-easterly from Little Presque Isle, the point referred in a south-westerly direction. The precise limit of the to as the most southeasterly prolongation of the granite, primary rocks to the westward, has not yet been this last rock passes almost insensibly into a serpentine determined, but they are known to extend nearly or quite rock, which has a regular jointed structure, sometimes to the sources of the Wisconsin river. approaching to stratification; continuing in the same direction, we find a series of hornblende slates, talcose, A portion of the south-westerly prolongation of the mica and clay slates, resting against the serpentine Porcupine mountain range, is made up of rocks rocks, and still farther to the south-east the rock belonging to the primary group, but is precise limit here becomes almost uniformly quartz. The rocks of this has not yet been determined. group dip irregularly to the south and south-east, while 2. Trap Rocks.—Flanking the primary rocks already the cleavage of the slates is very uniformly to the north. described on the north and north-west, are a series of The rocks of the metamorphic group stretch into the ranges of hills, stretching in a direction generally south- interior, in a westerly or rather south-westerly direction, westerly and north-easterly, which attain an altitude of forming the south-easterly part of the hilly region. from three to nine hundred feet above the lake. They are more regular, or rather less broken in outline than Rocks referable to this group also occur upon the north the primary hills; a change, how ever, which in the coast of Lake Superior. transition is noticed to take place gradually, from one 4. Conglomerate.—The rock to which I shall restrict this group to the other or in other words, the knobbed term, does not occur, well characterized, at any point character of the ranges becomes less and less apparent east from the district referred to, as the commencement as we cross them in a north-westerly direction, or from of the trap group, nor has it been noticed resting upon the primary range. These hills are composed of rocks any of either the primary or metamorphic rocks, but is differing at first but slightly from those of the primary invariably seen resting upon the trap rocks. group, but gradually the difference becomes more and Commencing upon the north side of the trap, at the more apparent, as we proceed northerly. The rocks of extremity of Keweenaw point, the conglomerate flanks those hills nearest the primary range may possibly be the trap upon its northerly side, as far west as the regarded simply as rocks of that group, more or less boundary of our state; nor does it stop here, for the altered, though the rocks of the outer ranges are plainly same rock is seen at intervals, as far west as the head of trap. The range of these rocks which may be said to Lake Superior. A similar rock also rests upon the trap of commence at the very extremity of Keweenaw point, Isle Royale, facing the south-east. extends, after a slight curve to the north, in a general south-westerly direction, gradually receding from the In the course of the range of conglomerate upon the coast, until at the crossing of the Ontonagon river, it is south shore, it forms a nearly continuous range of hills, Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 5 of 59 with somewhat steep escapements, but with a generally sandstone; for even the primary trap and conglomerate rounded outline. These hills sometimes rise to a height rocks are almost invariably skirted with a band of it. It is of from three to five hundred feet above the level of the also over this rock that the waters of Lake Superior are lake. discharged at the Saut de Ste Marie. The conglomerate attains a very great thickness, being The sandrock forms the chief portion of the group, the greatest at its westerly prolongation, and it gradually shales occurring rather as beds than otherwise, as will thins out as we proceed north-easterly; but the be hereafter described. irregularity in thickness is so very considerable that The red sandstone both upon the north and south variations of several hundred feet are not uncommon shores of Lake Superior, invariably dips into the basin of within the space of a few miles. that lake, which may therefore be regarded as a The conglomerate rock of the south coast, dips in mass synclinal axis. irregularly to the north and north-west, while that of Isle 7. Upper or Gray Sandstone.—Upon the south shore of Royal dips to the south-east. Lake Superior, and extending from Point Iroquois to 5. Mixed Conglomerate and Sandstone.—The rock or Grand Island, a sandstone occurs, differing widely in its rocks to which I have affixed the above name consists of appearance from that before described. This sandstone an alternating series of course conglomerates and red rests unconformably upon the red sandstone, the former sandstones, resting conformably upon the conglomerate dipping gently to the south or south-east, while the latter rock before described. In strictness, these rocks should dips very considerably to the north or north-west. probably be considered as a member of the The elevated range of hills before described, as conglomerate itself, but for the sake of convenience in commencing a little easterly from Point Iroquois and description, I have deemed it desirable to separate them. extending to the Pictured rocks, are composed of this The mixed rock was only noticed, as before stated, rock. From the Pictured rocks, the range of hills curves resting upon the conglomerate, and this only between more to the south, stretching very far to the south-west, Point Keweenaw and Montreal river. Its thickness but its precise limit is not yet determined. immediately west from and upon the flanks of the In its easterly prolongation the grey sandstone thins out Porcupine mountains, is very considerable, but it rapidly. It is last seen at the Neebesh rapids of the wedges out rapidly both easterly and westerly, and on Riviere Ste Marie, on the east, at which point, in the east, near the extremity of Keweenaw point, it wholly consequence of not having been sufficiently examined disappears. farther westerly, it was confounded with the red The mixed rock dips regularly to the north and north- sandrock in the last report which I had the honor to lay west. before you. 6. Lower, or Red Sandstone and Shales.—The red 8. Sandy Lime Rock.*—Resting immediately upon this sandstone, with its accompanying red and gray shales, upper or grey sandstone is a sandy limerock, which, occupies a much larger extent of the country bordering although nearly wanting at the very easterly extremity of upon Lake Superior than any other single rock or group the peninsula, as we proceed westerly, occupies a more of rocks. It rests upon the primary and metamorphic important place. rocks, immediately west from Chocolate river; upon the *The names which have been affixed to the several sand and lime conglomerate and mixed rocks from near Eagle river, of rocks are regarded as merely temporary, and are introduced, for the Keweenaw point, west to the head of Lake Superior; present, barely to facilitate description. upon the primary trap, metamorphic and conglomerate rocks of the north shore of the lake, and upon the This rock, which, as its name implies, is intermediate conglomerate rock of Isle Royale. It is this rock which between a sandstone and limerock, may be seen on forms the basis of the level plateaus or valleys, Sailor’s encampment island of the Riviere Ste Marie, as occupying the spaces between the several ranges of also at several points in the vicinity of Monusco bay, hills south from Lake Superior, and west from Chocolate from whence it stretches westerly, occupying nearly the river. In these last situations this rock is frequently seen central portion of the peninsula, for a distance of at least undisturbed to surround the bases of isolated knobs of sixty miles; from which its precise range and limit has not granite, though when near to or in contact with knobs or yet been determined. The outcropping edge of this rock trap, there are invariable evidences of very great appears at a level very considerably below that both of disturbance. the sandstone to the north, and of the limestones to the south. Its width, for the distance mentioned, varies from The rocks of this group attain their greatest thickness at ten to fifteen miles, and it dips uniformly to the south- their westerly prolongation, gradually thinning out as we south-east. The sandy limerock has not yet been proceed easterly. examined with sufficient care to admit of accurate With the exception of that portion of the coast extending description. It contains but few fossils, but those few are from Point Iroquois, at the foot of the lake, to Grand sufficiently characteristic, were there no other Island, the predominating rock upon the immediate considerations, to separate it from the lower limerocks coast, both on the south and north shore, is this red and shales. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 6 of 59 Upon the sandy limerock, to which reference is above PRIMARY ROCKS. made, rests the lower limerock and shales, and upon Although the usual ternary compound of quartz, feldspar this last the upper limerock, both uniformly dipping to the and mica, occurs but rarely in the primary, in the vicinity south or south-east. These limerocks were described in of the coast of Lake Superior, and in fact but rarely in general terms, in my third annual report, and although any portion of the range which I have visited, many additional facts have been gathered respecting nevertheless, the great mass of rocks included within their character, range and extent, it is, perhaps, this range, may, in a broad sense, be called granite. unnecessary to lay them before you at this time. I will The compound above referred to is more common in the barely add, with respect to them, that the suggestion westerly than in the easterly portion of the range. The there mentioned, that a more careful examination of more common rock is made up of quartz, feldspar and these limestones would render a farther division of the hornblende, giving rise to a very dark colored syenite; groups necessary, has been fully confirmed. occasionally mica enters sufficiently into the compound I had hoped to lay before you a profile section of the to form syenitic granite, and sometimes the place of the rocks of the upper peninsula, but the impossibility of hornblende in the syenite, is supplied by schorl or having it engraved in time to accompany this report, has tourmaline, thus giving rise to a schorl rock. led me to defer it. I regret this the more, since many of The rocks of the southeasterly portion of the primary the facts connected with a full understanding of the range of hills are more clearly defined as granitic rocks, economical portion of this report, are so intimately than those situated more northerly, for they are more dependent upon the general geology of the country, that, distinctly and largely crystaline in structure, and quratz in the absence of correct maps, and without a profile enters much more largely as a constituent into their section of the rocks, I fear it will be impossible for me to composition. As we proceed north-westerly, from the render the most important portion, so far as regards the south-east boundary of the primary, over the several prosperity of the state, intelligible. broken ranges of hills, we find the character of the rocks As it is, I can only, in the place of this, lay before you a in mass almost imperceptibly changing. The quartz as a general section of the rocks of the upper peninsula, mineral gradually forms a less important part, and it together with their thickness, so far as the same has finally almost wholly disappears, leaving a binary been satisfactorily determined. This section is intended compound of feldspar and hornblende, which then simply to represent the order in which the several rocks assumes a granular structure, constituting greenstone. rest upon each other. The intermediate rock, between the syenite and greenstone ranges, may not inappropriately be called a Having already described in general terms the range and syenitic greenstone. extent of the rocks of the upper peninsula, so far as the same have been examined, the limits of the present The primary rocks which appear in the vicinity of Lake report will admit of nothing more than a general Superior, in the several ranges of hills extending from a description of the characters of these rocks, and I shall point opposite little Presque Isle,* to Huron river, are not attempt a minute description of any members of the essentially either syenite or syenitic granite. The rock, series, except such as are more or less connected with as a whole, is extremely compact, and the constituent subjects which are supposed to be of immediate minerals are mostly in small crystals, though practical importance. occasionally the feldspar assumes a more largely crystaline form. The granitic rocks, so far as the range has been examined, in a southwesterly direction, are largely traversed by dykes, that are almost without exception made up of materials in all respects identical with the greenstone, before alluded to, as forming the more northwesterly ranges of hills. The courses of these dykes or veins are invariably marked by striking changes in the character of the rock traversed, and in the larger dykes, the evidences of the changes produced by the heat of the injected matter, extend to several hundred feet upon either side of the dyke itself. The connection between the rocky matter composing these dykes and the ranges of greenstone, lying northwest, is clearly identified, not only by the perfect similarity in mineral character, but also from the fact, that as we proceed in the direction of the ranges of greenstone, the dykes become much more frequent, until at length it becomes difficult to determine which of the rocks predominate in quantity.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 7 of 59 These facts serve to throw much light upon the relative greenstone, with occasional narrow bands of sandstone; ages of the several ranges of hills, or in other words, thus precisely reversing the magnetic order of those serve to show the order in which they were severally rocks upon the south coast. uplifted; facts TRAP ROCKS. *A little southeast from River Des Morts. Were we to consider the rocks of the district under which will be more fully shown when we come to consideration, strictly in their chronological order, those consider the present position of the overlying rocks which I propose to treat as trap rocks, would sedimentary rocks. These facts are not only important, undoubtedly follow those slates and quartz rocks which to enable us to understand the many changes which are considered as metamorphic, and which may be have taken place, with regard to the relative position of regarded as identical in time of up lift with those rocks the land and water, but they are rendered of practical before alluded to, as being intermediate between the importance for the reason, which I think may be granitic and trap rocks. The almost insensible satisfactorily shown, that the mineral region of the upper gradations by which the granitic rocks pass into the peninsula, to be hereafter described, is strictly confined greenstone of the trap formation, and the near analogy to only the outer portion of the rocks of a single epoch. of the whole of the rocks of both formations, to each other, renders it more convenient, at the same time that The veins and dykes of greenstone, referred to as it is more simple to follow the arrangement or order that I traversing the granite rocks, do not, in this portion of the have adopted. group, appear to have any regular magnetic bearing, for they traverse the rock in all directions. Veins of any I have already stated that in passing from the granitic other matter are very rarely seen traversing the granite. region on the south side of Lake Superior, in a direction In a single instance, what was regarded as a true vein of northwesterly, we cross a series of ranges of hills, porphyry, having a width of nearly three feet, was varying in height from three to nine hundred feet above noticed, which vein is crossed, at angles of 53° and the lake, and that in pursuing this course, we observe 107°, by a vein of greenstone, having a width somewhat that the character of the rocks gradually and almost less than that of the porphyry. In this instance, the insensibly change, until at length they become well greenstone is clearly the most recent vein. defined greenstone.* The veins of greenstone traversing the granite, vary from The rocks of the outer or northwestern range of hills, a mere line, to 50 or 60 feet in width. The intimate which were clearly the last of the series of uplifts, bears blending of the material composing these veins, together more unequivocally the evidences of igneous origin, than with the chemical differences, causes them to either of the outer ranges alluded to. The rock upon the disintegrate or waste away more rapidly than the rock south flank of these hills, is invariably very compact they traverse; the result of which is, that deep grooves greenstone, while upon the north-westerly line it is are frequently left in the granite, the simple result of the almost equally invariably an amygdaloid, or at least, has wasting away of these dykes or veins. This is peculiarly an amygdaloidal structure. The causes of this difference the case upon the coast of the lake, where the rocks are of structure of the rock, upon the opposite sides of this subject to the action of the waves, which have, in some range of hills, when carefully examined upon the ground, instances, so removed the debris as to leave long and are very apparent; for it is evident, as will hereafter be narrow bays, with high perpendicular walls, occupying shown, that the uplift of the rocks of this range of hills simply the space once occupied by the dyke. The Huron was wholly upon the south-easterly side, and while the islands, which are simple elevated granite knobs, rocks of this portion were in a solidified state, or, in other appear, upon first examination, as a mass of rocks, words, that a point in Lake Superior may be regarded as completely rent in many places, with portions separated the fixed axis of the uplifted mass. That this was the from each other by narrow clefts, having perpendicular case, is shown by the fact that the sedimentary rocks to walls of great height. While these rents are of sufficient the south or south-east are width to admit of being traversed by small boats, the *In the present report, I use the term greenstone, in its generic sense, perpendicular walls are so little varied in their elevation applying it to all the compact rocks, of a granulated structure, as scarcely to leave a point, in these narrow passages, belonging to the trap range. By far the larger proportion of these rocks where a landing can be effected. A careful examination are greenstone, in its most restricted sense, or in other words, are of these passages shows them to be simply the spaces composed of feldspar and hornblende; but the term is also used to include rocks which in a strict sense would be considered as altered once occupied by dykes or veins of greenstone, which syenite, syenitic granite, hornblende rock and angitic rock. having disintegrated, and the detrital matter having been The term amygdaloid, I apply, as it is usully applied to that portion of removed by the action of the waves, have left the walls the rock having a difference of form simply, without any reference to of the more enduring granite rock, unbroken and almost the constituents of the rock. This generic use of terms is imployed for untouched. the reason that the limits of the present report will not allow anything more than a very general consideration of the subject. The term trap is Upon the north coast of Lake Superior, well defined used in a such a sense as to include both the greenstone and granite and syenite, or syenitic granite, occasionally amygdaloid, though it may sometimes prove that the aymgdaloid has appear upon the immediate coast of the lake, but more had its origin from the fusion of the lower portions of the sedimentary rocks. frequently these rocks are flanked on the south by

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 8 of 59 scarcely disturbed, so far as regards this range of hills, Keweenaw point, this line passes in a southwesterly while the sedimentary rocks on the north or north- direction, gradually receding from the coast; it crosses westerly side, are invariably tilted to a high angle, near Sturgeon or Portage lake near its centre, after which it the range of hills, which angle gradually decreases as recedes still more rapidly from the coast, until finally it is we pass farther and farther from the hills themselves. seen to cross the upper forks of the Ontonagon river, These sedimentary rocks, which upon the north side and soon after the whole is apparently lost in the range always dip from the range of trap hills, are in their close of the Porcupine mountains; which last range has a proximity to the trap, inclined at angles varying from 45° course so much to the south-west as probably to to 85°. Dykes of from fifty to four or five hundred feet, completely intersect the first range mentioned. On the are of frequent occurrence, traversing these sedimentary west side of the Porcupine mountains, the range of hills rocks, but the widest of these have invariably been and the line of junction appear again, but many miles protruded between the strata of the sedimentary rocks, farther north than they would have been looked for; from and consequently have the same general inclination. thence the true line gradually approaches the coast, The result of these frequent dykes, which occur at until, at its point of crossing the Montreal river, it is but comparatively short distances from the main body of about 2 miles above the mouth of that stream. trap, is that the sedimentary rocks frequently so far loose To the north and north-west, through the whole of the their original character as scarcely to be recognized. distance described, this trap is bounded by hills of The rocks of the complete north-western escarpment of conglomerate and sandstone, more or less elevated, but this range of hills, were evidently in an intense state of usually not exceeding 400 feet. To the north-west of ignition while in contract with the sedimentary rocks, as these hills of sedimentary rocks, a dyke of trap is seen to is clearly shown by the very great changes which have extend for many miles along the line of coast of taken place in the rocks last alluded to. In fact, I am Keweenaw point, and so great is the width of the dyke, disposed to refer the origin of much of the amygdaloid that, unless carefully examined, its character might rock to the fusion of the lower portions of the easily be misunderstood. It lies in a plane parallel to the sedimentary rocks referred to, for the reason, that as we stratification of the sedimentary rock by which it is pass south from this junction, the amygdaloid rocks embraced, and with that rock dips to the north-west. wholly disappear, their place being supplied by The dyke is chiefly made up of greenstone, but not greenstone; and again, so intimately are they blended, unfrequently large portions of the mass consist of that it is frequently impossible to determine where the amygdaloid, in which the amygdules are filled or amygdaloid ceases, and the upper sedimentary rocks composed of quartz, chalcedony, agate, calc. spar, commence. Fragments of the sedimentary rocks, the zeolite, &c. characters of which can be clearly recognized, are not of The dykes just referred to, so far as their relation to the rare occurrence, imbedded in the amygdaloid rock, a amygdaloidal portion of the trap is concerned, as also circumstance which although by no means conclusive, the many others similarly situated with respect to the should not be overlooked in considering this subject. superincumbent sedimentary rocks, will be regarded in I would not wish to convey the idea that the amygdaloid the same light as contemporaneous veins, though they rocks have their origin exclusively from the altered are only contemporaneous with the uplift of the strata, sedimentary rocks, but simply that the change in the and not with their deposit. But there is still another class structure of the trap, from greenstone to amygdaloid, of veins which not only traverse a portion of the trap may and no doubt does depend upon the proximity of rocks, but also the upper sedimentary rocks, and which the sedimentary rocks to the trap, while the latter was in may be regarded as true veins. These last mentioned a state of ignition. veins traverse the rocks at a high angle with the line of bearing of the sedimentary rocks, as also with the line of I have been compelled to tread upon grounds which junction of those last mentioned with the trap rocks. The may, perhaps, be considered theoretical, but it would composition of these veins is widely different from that of appear to be necessary in order to convey a proper idea the contemporaneous veins or dykes before referred to. of the condition of the rocks composing the range of hills As this subject will be treated more at length in a under consideration. These views, however, would not succeeding portion of this report, I deem it unnecessary have been alluded to at this time, had it not been for the at this time to refer more particularly to the subject. fact, that an understanding of all that relates to the mineral resources of this portion of our state, is more or A single knob of trap appears under circumstances less intimately connected with this portion of the subject. which add very much to its interest, at what is usually known as Presque isle, an elevated rocky point Although the general range of the trap hills has been immediately north-west from Riviere Des Morts, and already given, I will define, as nearly as is in my power, almost directly within the granitic region. This point of the line of junction between the trap and sedimentary land has its origin from the simple elevation of a mass of rocks, upon the north escarpment, premising that the trap rock, which rises on the north in abrupt cliffs, elevation at which this junction takes place, is usually at varying from 20 to 60 feet in height. The trap is mostly a height of from 100 to 500 feet above the lake, and only greenstone, though portions of it are so largely in a single instance does this line reach the coast of the lake. Commencing almost directly at the extremity of Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 9 of 59 impregnated with a dark colored, almost black termed a rudely columnar structure. Upon one of the serpentine, as to deserve the name of serpentine rock. long rocky points forming the north-easterly extremity of Isle Royale, this rock assumes the columnar form, and The knob of trap under consideration, is possessed of the columns are tolerably well defined, having a height of additional interest, from the unequivocal evidence of from 80 to 90 feet. The columns are also seen, but less uplift, as also from the manner in which these evidences perfectly developed, forming the coast of a small rocky are exhibited. The cliffs of trap occupy the very island, two to three miles south from the point last extremity of the point, while the neck and central alluded to. These are the only points in the trap of Lake portions are made up of conglomerate or trap-tuff and Superior, where I have noticed the rock to assume this sandrock, resting upon the trap. These upper rocks also form. appear upon the immediate coast, in cliffs of from 20 to 60 feet in height, and in many places they are seen METAMORPHIC ROCKS. resting directly upon the trap. The stratification of these The general direction of the rocks composing this group, sedimentary rocks has been very much disturbed, and has already been described, and they are confined they invariably dip, at a high angle, in all directions from exclusively to the range of hills lying upon the south-east the trap itself. The character of both rocks, at the side of the granitic rocks. The general direction of these immediate line of junction, is almost completely lost, and hills is south-west and north-east. the evidences of change most unequivocally marked. But the most curious feature of the whole is, that the The outline of the hills of the metamorphic group is less sedimentary rocks, for a distance of several hundred broken than either the granitic or trap ranges, but these feet, have been completely shattered or broken into rocks sometimes rise in abrupt conical peaks, closely minute fragments, which, having retained their original resembling those of the granitic rocks. position were again cemented by the injection of The area of country occupied by rocks of this group, is calcareous matter. This injection has filled the most less than that of either the primary or trap, the general minute fissures, and so perfect is it, that, in looking upon average width not exceeding six to eight miles. The the face of a mural cliff of these rocks, the veins may be precise limit of the group in a south-westerly direction, is easily seen at a distance of many rods, forming as it not known. were, a complete net work over the cliff, and so minute is it, that a single hand specimen frequently contains many It has already been stated that Chocolate river is the hundreds of these veins. boundary, on the south-east, between these and the This knob of trap, like the rock before described, is also sedimentary rocks, and that they extend in a north- westerly direction from this stream to the granite, against traversed by veins, of a date subsequent to the uplift of the rock. which they rest. The group is made up of an alternating series of talcose and mica slates, sometimes graduating The whole of the north-western portion of Isle Royale is into clay slates, with quartz and serpentine rocks, the made up of trap, and in truth that rock constitutes, by far, quartz rock constituting by far the larger proportion of the the largest proportion of the rocky mass of the island. whole mass. Since it would be nearly impossible to The two northerly ranges of hills, already alluded to as describe the alternations of these several rocks, in such traversing the island, in its greatest length, are wholly a manner as to be understood, without the aid of a trap. The most northerly range of hills, is composed diagram, or section, no attempt will be made to do so. almost exclusively of greenstone, while the rock of the south or south-easterly range, becomes more decidedly The cleavage of all these rocks is usually north or north amygdaloidal in its structure; thus reversing the order 10° west, at an angle, which, in the main, varies but little from 80°, but the mass of the group appears to dip which these portions of the rock bear to each other upon the south shore of the lake. regularly to the south or south west. The talcose slates and quartz rocks alternate frequently with each other; The ranges of hills immediately bounding Lake Superior and with the rock which has been called serpentine rock, upon its north coast, are almost invariably either well less frequently. defined trap or altered syenite, while the decidedly primary rocks usually appear in ranges of hills to the The quartz rock is usually distinctly granular, though it is sometimes compact, with a conchoidal fracture. It north of these; thus following the reversed, order of the rocks upon the south coast. usually separates by cleavage into masses, or strata, having a considerable - degree of regularity, and varying The character of the trap rocks of Lake Superior has from a few inches to several feet in thickness. The rock perhaps been sufficiently described, to answer the is usually more or less regularly jointed. purpose for which this hasty sketch is intended; and I will only add, that they are usually distinctly jointed, and That rock which, for the sake of convenience, I have where they approximate to the sedimentary rocks, there denominated serpentine rock, bears a close is not unfrequently so distinct a cleavage, opposed to the resemblance to greenstone, being essentially composed of granular feldspar and hornblende, with which joints in direction, as to give the appearance of stratification. The jointed structure of the trap rocks serpentine is intimately blended. This rock only occurs sometimes, though rarely, passes to what may be in the talcose slate as we approach the granitic region, and possibly a more close examination may show it to Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 10 of 59 be a simple series of dykes, lying parallel to the line of nearly or quite continuously, as far as Montreal river, cleavage of the slate rocks. which stream it crosses at a short distance above its mouth, thus making its complete length, within the limits The metamorphic rocks are occasionally traversed by of Michigan, computing its southerly curve, something trap dykes. The group of rocks under consideration has over 140 miles; but the rock does not cease at Montreal been comparatively little examined, and the more minute river, for it may be seen at short intervals in the interior, details connected with it will be taken up at some future as far westwardly as the head of Lake Superior. time. At the trap knob of Presque Isle the conglomerate is CONGLOMERATE ROCK. imperfectly developed, but on the south-westerly side of The lower of the sedimentary rocks, to which I have Isle Royale, it is more perfectly developed, flanking the attached this name, appears to be invariably connected hills of trap upon the southerly side. with, or to rest upon, the trap rock, nor has it been The conglomerate rock is imperfectly stratified, in noticed, to any extent, in connection with either of the masses of immense thickness, and it dips, upon the other lower rocks, for it wholly disappears as we south shore of Lake Superior, regularly to the north, and approach the granitic and metamorphic groups. Of all north-west,* usually at high angles, varying from 30 to the sedimentary rocks, this is the most variable in 85°, while upon Isle Royale and the north shore, the dip thickness, and not unfrequently does a few miles make a is reversed, being south difference of several hundred feet. The conglomerate rock may, without doubt, be considered as a trap-tuff, *This variation in the dip is in conformity with the variation in the which was gradually deposited or accumulated around direction of the trap hills. the several conical knobs of trap, during their gradual and south-easterly, or in other words, the rock upon all elevation, and which would necessarily occupy the sides dips in the direction of the lake basin. complete spaces or valleys between the several irregular ranges of knobs or hills. Upon the south shore of the lake, the thickness of this rock was not estimated at any point west from Montreal If we regard this conglomerate rock in this light, we will river, a little east from which, it attains its greatest at once perceive why the rock should be variable and thickness, being, as estimated, 5,260 feet. In addition to irregular in its thickness. the great variations in thickness, over comparatively The pebbles of which the mass of the rock is composed small districts, the formation wedges out as we pass consist of rounded masses of greenstone and easterly along the range, and so rapid is this change, amygdaloidal trap, of which the former make up by far that near its easterly prolongation the thickness was the larger proportion, and scarcely a pebble of any other estimated at something less than 1,000 feet. rock than trap, enters into its composition. These The greatest estimated thickness of the rock upon the pebbles vary in size from that of a pea, to several north coast, is a fraction less than 2,800 feet. pounds weight, but the average size may be stated at 1½ to 2 inches in diameter. The pebbles are usually I have already stated that this rock is frequently united by a mixed calcareous and argillaceous cement, traversed by dykes of trap, which are usually parallel to more or less colored by iron, and so firm is this union, the line of stratification and dip of the rock. These that the most compact and tough of the greenstone dykes, which have sometimes a thickness of 50 to 60 pebbles, will frequently break through as freely as the feet, and even several hundred feet, are sometimes cement, and crevices and narrow veins are frequently continuous for many miles, and are many times seen passing indiscriminately across the pebbles and repeated. In addition to the dykes just alluded to, the cement. This fact is the more worthy of notice, since the rock is frequently traversed by veins of a more recent pebbles are almost without exception, made up of the date, which traverse alike the trap and conglomerate hardest and most indestructible portions of the trap rock. rocks, always at very high angles with the line of bearing of the conglomerate. These veins, which are usually The conglomerate rock can scarcely be said to occur in more perfectly developed near the line of junction of the such form as to be well defined, in any portion of the two rocks, or for a distance of a few thousand feet upon country, excepting upon the northern flank of the outer each side of the junction, are clearly true veins, and trap range, before referred to. On the outer or northern since, with a few unimportant exceptions, they are the side of Keewenaw point, the conglomerate commences only veins belonging to this range which are near the extremity of the point, and extends several metalliferous, they will be considered more fully under a miles westwardly, forming a series of abrupt and separate head. precipitous cliffs upon the immediate shore, as also, a range of well defined hills, a little in the interior; which MIXED CONGLOMERATE AND SANDROCK. hills have an elevation varying from 200 to 800 feet. This rock formation is made up of an alternating series of After appearing for a few miles upon the coast, this rock conglomerate and red sandstones, which rest gradually stretches into the interior, following the line conformably upon the conglomerate rock last described, before described as the most northerly boundary of the dipping with that rock, into the bed of Lake Superior. outer trap range of hills, and invariably occupying a The mixed rock was not noticed upon the north side of place to the north of this range, and it may be observed, Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 11 of 59 the lake, or upon Isle Royal, but upon the south shore composing the dykes appears to have been injected in a the rock was traced continuously for a distance of about plane corresponding with that of the stratification of the 130 miles, extending from a few miles westerly from the embracing rock. As in the conglomerate below, these extremity of Keweenaw point, to Montreal river. It dykes have produced very great changes in the color follows the line of the conglomerate before described, and structure of the mixed rock bounding them upon stretching from Keweenaw point, in a south-westerly either side. direction, and again curving to the north-west, forming, In addition to these, the mixed rock is occasionally, as it were, a crescent between the points before (though less frequently than the rock below,) traversed mentioned, the result of which is, that the rock only by veins or cross courses of a more recent origin than appears for a very limited distance upon the coast of the the dykes, (which latter they usually cross at a high lake, at Keweenaw point. angle,) their course usually being at an angle of at least From a point about 18 miles easterly from Montreal river, sixty degrees, opposed to the line of bearing of the the rock wedges out rapidly as we proceed westerly from mixed rock. These cross veins are usually made up of that point, and as we continue towards the head of Lake calcareous spar or a sub-granular limestone, and more Superior, the rock wholly disappears, or becomes rarely of some variety of quartz, and imperfect trap rock, merged in the conglomerate rock below, and the the latter of which is usually of the amygdaloid variety. sandrock above. The greatest observed thickness of RED SANDSTONE AND SHALES. this rock is 4,200 feet. That rock to which I have applied the name of red The conglomerate portion of the mixed rock consists of sandstone, is emphatically the chief rock that appears strata of conglomerate, varying from a few feet to upon the immediate coast of the south shore of Lake several hundred feet in thickness, and it is composed of Superior, and the same remark will apply, in a more materials in all respects resembling those constituting limited degree, to the complete coast of the lake. A the conglomerate rock before described and these traveller proceeding westerly along the coast, from materials are united by a similar cement. Grand Island to the head of the lake, would imagine he The sandstone portion of the formation occurs in strata had seen little else than red sandstone, and in fact, were of very nearly corresponding thickness, and the two he to confine his examinations to the immediate coast, rocks may be said to form nearly equal portions of the he would see no other rock for nineteen-twentieths of the complete mass. But the material of which this distance. From Grand Island westerly to the mouth of sandstone is composed differs widely from that of the Chocolate river, no other rock is seen in place, and from true sandrock lying above, for while the latter is chiefly Chocolate river to Keweenaw point, embracing the made up of quartzose materials, the former is composed complete width of the primary, metamorphic and trap of materials bearing a close analogy in composition to ranges, the hills forming these groups are almost those of the conglomerate rock itself; or in other words invariably surrounded or flanked at their bases, by this the sand consists chiefly of greenstone, so much sand rock, so that even along this portion, the hills are, comminuted as, when cemented, to compose a coarse for a large proportion of the distance, cut off from the sandstone. It will thus be seen that the members of this lake by a narrow belt of the rock under consideration, formation differ only in the degrees and fineness of the and westerly from Keweenaw point to the head of Lake material, and the character of this material will explain Superior, no other rocks appear upon the coast, if we sufficiently why the true conglomerate, and the mixed except several trap dykes in the vicinity of the Porcupine rocks are referable to the same origin, for the materials mountains, and a series of more recent deposits of clay of the several members of the group have their origin and sand, that appear west from Keweenaw point. This from the trap rock, and as a whole may perhaps be sand rock also occurs upon the southerly side of Isle regarded as a trap-tuff. Royale. The coarser conglomerate of the formation is scarcely The material of which the red sandrock is composed, separated by lines of stratification, and the strata differs widely from that of the sedimentary rocks before appears usually in mass, embraced between the strata described, for while the rocks last referred to are made of .sandstone, but the stratification of the latter rock is up of materials clearly of trappean origin, and in which perfect, and it bears evidence of having been deposited the material is very rarely quartz, the rock under in shoal water, in the very abundant, perfectly defined consideration is composed of materials, the ripple marks which it exhibits through its complete range. predominating portions of which are clearly derived from the granitic and metamorphic rocks, and in which quartz No fossils were noticed in connection with either the occurs abundantly, though with this, there is usually mixed rock, or the conglomerate lying below it. associated more or less sand, that has all the characters Dykes of greenstone occasionally appear in the mixed of the comminuted trap, constituting that portion of the rock, but less frequently than in the rock below. These mixed rock before referred to. Magnetic iron sand, dykes almost invariably occupy places between the sometimes becomes a constituent of the red sandrock, strata of the rock, and correspond in position to the and occasionally continuous strata of several inches direction and dip of the rocks by which they are thickness, are almost wholly composed of this material. embraced, or in other words, the rocky matter The material composing this rock is usually cemented by Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 12 of 59 calcareous matter highly colored by the per oxyd of iron, shoal bays of Lake Superior. Fossils are rare in the red though not unfrequently these are associated with sandstone, and in fact, I have never seen any other than argillaceous matter. fucoides, of which there are three species, that are tolerably well defined. While the chief mass of the rock is a coarse grained, somewhat compact, sandrock, there are portions of the The red sandrock is less frequently traversed by dykes formation where there are well formed red and grey of trap than either of the rocks before described, though flags, and red and green shales, forming, as it were, dykes were sometimes noticed traversing the whole of beds of a very considerable thickness, and occupying the several rock formations, up to and including the red large districts of country. These red and green shales sandstone. Upon portions of the north coast, where the are more largely developed in that district extending from conglomerate and mixed rocks are more frequently Granite point westerly to Keweenaw bay, and upon the wanting, and where the red sandrock is brought more south side of Keweenaw point, extending from the head nearly in contact with the trap, these dykes are of more of the bay to near the extremity of the point, they are frequent occurrence. It is deserving of remark, that particularly largely developed. These shales more where the lower rocks are either wholly or in part usually occur in alternating bands of deep red and green wanting, the red sandstone usually becomes of a deep colors, the red usually largely predominating, and they brown color, and the material of which the sand is are made up of argillaceous matter, with sand, the whole composed, gradually changes from that before of the materials being of extreme fineness. described to greenstone. On the south-east side of Keweenaw bay. near its head, I have already stated that the sandrock, at its westerly an argillaceous rock appears, and extends for a short prolongation, attains its greatest thickness, which was distance along the coast, which is an anomaly. The rock estimated at 6,500 feet, but as the rock continues is evidently embraced in, or rather may be said to easterly, it gradually and quite regularly diminishes in constitute a member of the sandstone series, but it thickness, and beyond Saut de Ste Marie, the thickness differs widely from any other rock seen in connection is very inconsiderable. The average rate of diminution with it. This argillaceous rock sometimes appears in the which takes place in the thickness of the rock as we form of a slate, though its most usual form is that of proceed easterly, was shown by a great number of compact strata, frequently of several inches thickness, observations, upon the south-westerly portions of the and which closely resembles indurated clay. A peculiar coast of Lake Superior, to be a fraction over fifteen feet appearance is given to this rock by the innumerable to the mile, but this rate of decrease could not be layers or very thin strata, which compose the mass, satisfactorily estimated upon the lower or easterly half of being of different colors, sometimes red, grey and dark the coast. The red sandrock thins out as we proceed brown, alternating in the same hard specimen. southerly or inland from the coast, at a still more rapid rate, as was most satisfactorily shown, where it is The material of which this argillaceous rock is connected with the several primary, metamorphic and composed, possesses an extreme degree of fineness, trap ranges of hills, for all or nearly all the valleys, after and is so soft as readily to be cut with the knife, which passing the outer or northerly range of trap hills, are qualities render it a fit material for the manufacture of based upon this sandrock, and since we have every pipes, to which purpose the Indians of the country have reason to believe that this sandrock was deposited in long applied it. It has also been applied to use in part, during the gradual elevation of the several chains of sharpening tools, but its softness is a serious objection hills, it would follow, that over those districts which were to its use for that purpose. last elevated, the rock would attain its greatest A similar argillaceous rock also appears at several other, thickness. I have already alluded to the order in which points in the interior, or southerly from that already the several ranges of hills appear to have been uplifted, described, but as yet I have been unable to determine its and since more particular reference will be made to this thickness at any point. The finely represented bands or hereafter, I leave the subject for the present. zones, which may fairly be supposed to represent the The red sandrock south from Lake Superior, as well as original lines of deposition, are very much contorted, and upon the immediate coast, dips regularly northerly, while in such a manner as to lead to the conclusion that this that upon the north coast dips invariably southerly, or, as change must have taken place very soon after the has already been said of the lower rocks, this rock dips, deposition of the rocks, and while they were still in an upon all sides, regularly into the basin of the lake. The unindurated state. quantity of dip is exceedingly variable, being always very The rocks belonging to the red sandstone formation, much increased as it approaches the trap, and bear the evidence of having been almost universally diminishing as it approaches the primary and deposited in shoal water, for ripple marks occur metamorphic ranges. abundantly at all points where the rock takes on the The line of cleavage of some of the members of the decided character of sandrock, and these ripple marks lower sandrock and shales is frequently irregular, and may frequently be seen, for many rods together, as opposed to the true stratification of the rock. distinctly and clearly defined as they are at the present day in the loose sands forming the bottom of some of the

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 13 of 59 UPPER OR GRAY SANDROCK Stratified clays and sands, similar to those skirting the borders of the lower peninsula, are seen at many points, The only remaining rock which separates the red and continue for long distances upon the coast of Lake sandrock from the limestones lying to the south, is a Superior; and they are also largely developed at many gray, or brownish sandrock, that is almost wholly points in the interior of the country. These deposits composed of grains of quartz, usually feebly cemented sometimes attain a thickness of from 200 to 300 feet, with calcareous matter. The composition of this rock and they are spread over the less elevated portions of differs from that of the lower sandrock, in being more the district. The character of these clays and sands bear exclusively quartz, while in epoch of deposition, the rock a close resemblance to those described in a previous under consideration should not be confounded with that report, as occurring upon the lower peninsula. of the red sandstone. It has already been stated that the red sandrock of the south coast, dips regularly northerly, while the upper or gray sandstone dips equally regularly ECONOMICAL GEOLOGY. south or south-easterly, in which respect the last Rocks. mentioned rock conforms to the limestones resting upon it, while it rests itself upon the uptilted edge of the red The series of limerocks resting upon the sand rock last sandrock, below. described, were noticed in the report which was laid before you at a previous session, and the limits of the I have already stated that this rock was first noticed, present report will not permit me to refer to them, more rising in hills, at a point not far distant from Riviere Ste fully, at this time. My observations will, therefore, only Marie, and south-east from Point Iroquois; from this include those rocks which lie below the limestones. It point, it stretches westerly in an elevated and very will be borne in mind that the whole of the group of regular chain of hills, that are upon the coast, as far as limestones are embraced in the southerly portion of the Tequoimenon bay; westerly from which the shape of the upper peninsula, and that their outcropping edges do not coast is such that these hills do not again appear upon it, reach within many miles of the coast of Lake Superior. until we reach that precipitous portion of the lake coast This is an important fact, for it shows the whole of the known as the Pictured rocks, where the fury of the northern part of the upper peninsula to be deficient in waves, aided by frost, has acted upon the feebly materials for the manufacture of lime, which are, in truth, cemented material of which the rock is composed, to wholly wanting. such an extent as to leave large portions of what was originally the northern escarpment of these hills, along Materials adapted to the purposes of building, abound, this coast, in high mural and overhanging precipices. throughout the district of country under consideration, Westerly from the Pictured rocks, the ranges of hills, and though they vary exceedingly in value for that which are composed or made up of this rock, stretch in a purpose, yet no portion of the country can be said to be south-westerly direction, passing completely to the south without a supply. of the primary, trap and metamorphic regions. The Among the most valuable of the materials for this westerly prolongation of this rock has not yet been purpose, the syenites and syentic gravites deservedly determined. rank first, and they occur of a quality which may be The upper sandrock, like the lower, abounds in clearly advantageously worked at various points in the primary defined ripple marks, and its line of cleavage is very range. Some of the syenites near the coast of the lake irregular, frequently being opposed to the line of are so situated as to be readily quarried, and they may stratification over very considerable districts of country. be made to furnish a beautiful and durable material for Two indistinct species of fucoides were all the fossils building. The color of these syenites is usually a very noticed in connection with it. dark gray, from the predominance of hornblende in the composition, but this is by no means invariably the case. I was unable to obtain any observations upon the thickness of the upper sandrock, which were The metamorphic group scarcely furnishes a fit material satisfactory, but from the imperfect observations which for use as a building stone, for the structure of its schists were obtained, I was led to conclude that the average would be an effectual bar against their use, and the thickness as far westerly as the Pictured rocks, does not difficulties of working the quartz rock will probably vary very far from 700 feet. The upper sandrock, like the prevent that rock being applied to that purpose. rocks before mentioned, wedges out as we proceed, in Some of the compact greenstones and altered syenites an easterly direction. of the trap range, may be made to furnish an excellent TERTIARY CLAYS AND SANDS. building stone, which, although in powers of resisting the action of disintegrating agents, may be less than that of As in the lower, so in the upper peninsula, the older the unchanged syenite, nevertheless possess a very rocks are more or less covered by deposits that may be great degree of durability. The greenstone ranges of severally arranged under the above head. To these hills, frequently for very considerable distances, are deposits it is my intention, at the present time, barely to made up of rock in which the jointed structure is so allude. perfectly developed, that regular blocks, of a convenient

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 14 of 59 size for building may be obtained, with comparatively Minerals of the Primary Rocks. little labor. The following list can by no means be regarded as The conglomerate rock is scarcely applicable to use for perfect, but it will serve, at least, to convey an idea of the purposes of building. small number of minerals which are found in connection A very good building stone may be obtained from many with the rocks of this group. portions of the lower, or red sandstone formation, and Schorl, Mica, though the cement of this rock is usually not very Tourmaline, Feldsdar, perfect, yet, frequently, such changes have taken place Hornblende, “ red, in the rock, that it has almost taken on the character of Actynolite, Quartz. granular quartz rock, in which cases, its durability is very Minerals of the Metamorphic Group of Rocks. much increased. The strata of this rock are usually of a Quartz, common, Iron, scaly red oxid of, convenient thickness to admit of being easily quarried, “ milky, “ hasmatite, and they are so regular that the stone will require but “ greasy, “ pyritous, little dressing. “ tabular, Steatite, The upper, or gray sandrock, being almost uniformly but Serpentine, common, Novaculite. feebly cemented, and sometimes decidedly friable, is of Of the minerals enumerated as occurring in the less value as a building stone than either of the rocks metamorphic rocks, the milky variety of quartz is before mentioned. Those portions of the upper sandrock abundant, sometimes composing almost entire ranges of where the calcareous cement imperfect, but not hills. The novaculite is also abundant, but of a coarse sufficiently hardened, might be rendered much more variety. This last is associated with the talcose slates. capable of resisting the action of the elements if allowed The remaining minerals appear either disseminated, or to remain under shelter a sufficient length of time to forming druses in the quartz rock, though sometimes allow this change to take place. they occur in thin beds or veins, in the talcose slate, The value of the limestones of the southern part of the which beds conform to the line of cleavage of that rock. peninsula, for the purposes of building, as also for the Although the hæmatite is abundantly disseminated manufacture of lime, was mentioned in a previous report through all the rocks of the metamorphic group, it does upon the geology of that district of country. As has not appear in sufficient quantity, at any one point that already been stated, these limerocks do not reach within has been examined, to be of practical importance. many miles of the coast of Lake Superior, and it is Minerals of the Trap Rocks. certainly to be regretted, that the shore of the northern Quartz, common, Steatite, common, portion of the peninsula is destitute of this important “ smoky, Asbestus, material. Nor have I seen any marls of sufficient extent, “ milky, Amianthus, in the district, to admit of application to any of the “ greasy, Calcareous spar, purposes to which it is applicable, or to supply, even in “ radiated, Copper, native, part, the deficiency in limestone. All the lime which ” mamillary, “ pyritous, would appear to be capable of being applied to practical “ drusy, “ black, purposes is that of the calcareous spar, composing the “ amethystine, “ red oxid of, veins traversing the sandrock, and these are not only Chalcedony, “ azure carbonate of, rare, but they are also of very limited extent. Carnelian, “ green carbonate of, MINERALS AND MINERAL VEINS. Jasper, “ “ “ ferruginous, Agate, common, Lead, sulphuret of, In considering this portion of the subject, I propose to “ fortification, “ carbonate of, treat the minerals of the different formations separately, Augite Iron, pyritous, so far as the same can be done, and although this Actynolite, “ red oxid of, method will necessarily cause some repetition, it will Serpentine, “ hydrate of, enable me to show, more perfectly than could otherwise “ pseudomorphous, “ silicate of, be done, the connection between those minerals that Chlorite, common, Manganese, ferruginous oxid of, may be regarded as of practical value, and the rocks to “ earthy, Silver, native, (very rare,) which they belong. Since a consideration of the minerals contained in the As a whole, the rocks of the upper peninsula are trap, will also involve a portion of those embraced in the deficient in number of minerals, though some few conglomerate, the mixed rock, and red sandrock and individual species occur abundantly. shales, I will, before referring minutely to those of the trap rocks, lay before you a list of those which occur most frequently in the sedimentary rocks last mentioned. The fact that veins of mineral matter, traversing the trap, are frequently continued across the several sedimentary rocks, and that dykes are of frequent occurrence in these latter rocks, would lead to the inference that there

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 15 of 59 would be a considerable degree of resemblance in the of the trap range, but also pass into the conglomerate, character of the minerals embraced in these dykes and and sometimes completely across the three sedimentary veins, in both the trap and sedimentary rocks, and to a rocks, immediately above the trap, thus having an certain extent, this inference would be true; but it should unbroken length of several miles. The class of veins to be borne in mind, as has already been stated, that the which I now allude, where they occur in a connected or veins, in traversing the several upper rocks, undergo continuous portion of the range, rarely vary more than very great changes in mineral character. 12° to 15° from a right angle to the line of bearing of the sedimentary rocks, and in pursuing this course, they Minerals of the Conglomerate, Mixed Rock and Red necessarily cut across the dykes of trap before alluded Sandrock. to as so frequently appearing between the strata, and Calcareous spar, Copper, native,† conforming to the dip of the lower sedimentary rocks. Quartz, common, “ pyritous,† “ milky, “ blue carb. of,† That the veins under consideration belong to a single “ drusy, “ green carb. of,† epoch, is inferred from the fact, that none have been Chalcedony,* “ earthy green carb. of,† noticed with other veins crossing them, as also for the Carnelian,* “ black,† reason that none have ever been noticed with Jaspar,* Zinc, siliceous oxid of, dislocations, heaves or disturbance of any kind, save Agate,* “ carbonate of, what may be referred to causes connected with their Iron, pyritous, immediate origin. “ black oxid of, (cemented iron sand,) That these veins must be regarded in the strictest sense “ red oxid of, as true veins, cannot be doubted, and that their origin or “ hydrate of, source, over the extended district alluded to, has been “ silicate of, the same, is inferred from the perfect identity of their *Occasionally occurring among the pebbles constituting the mass of mineral contents; for a description of one of these true the conglomerate. veins may be said to be essentially a description of the †Chiefly in those portions of the veins traversing the conglomerate. whole. Thus, while the mineral contents of the different portions of the same vein change as the rock traversed Mineral veins of the Trap. Conglomerate, &c. changes, the corresponding portions of different veins In order to render the subject of the mineral veins almost invariably bear a striking and close resemblance traversing the above rock, so far intelligible as may be in to each other. my power, I have already been particular to define, as These veins, as has already been stated, where they far as could be done without maps and sections, the traverse connected ranges of the trap, are regular in relation which the trap rocks, together with the course and direction, but when they are connected with superincumbent conglomerate, mixed sand and a single uplifted knob of that rock, they are irregular and conglomerate and red sandrock bear to each other, and can scarcely be defined, appearing, in the latter it will be necessary, in considering the mineral contents instance, rather as matter injected into the fissures of a of these rocks and the veins traversing them, to keep shattered mass of rock, than as connected veins. this relation constantly and clearly in view. The importance of carefully studying the relation which It will be recollected, that the north-westerly range of these veins bear to the rocks which they traverse, as hills, commencing at the extremity of Keweenaw point, also the relation which they bear to the numerous trap and stretching from thence in a south-westerly direction dykes, together with the few cotemporaneous veins into the interior, were referred to as being more clearly of noticed in the trap, is very much increased by the trappose origin than either of the other ranges, and that circumstance, that these veins are more or less the rock of the southerly portion of this range is either connected with, or rather contain, metallic materials, compact greenstone or altered syenite, while that of the which, it may be fairly inferred, will hereafter become of northerly flank is almost invariably either an amygdaloid very considerable practical importance. In fact, so far as or a rock approaching to toadstone. we may be enabled to judge from the examinations The several ranges of hills to the south of that last already made in this district of country, it is confidently alluded to, are either well formed, compact greenstones, believed that most, if not all the metalliferous veins of the altered syenite, or, (as we approach the primary range,) upper peninsula belong to veins of the epoch of those imperfectly formed granites. So far as the several under consideration. It is true that native metals, more ranges of hills, lying south from the northerly range, are particularly copper, are sometimes found, in place, concerned, they would appear to be, as a whole, occupying the joints or natural septæ of the greenstone, deficient in minerals, and the rocks are not apparently but in these instances, the amount of metal is always traversed by veins or dykes of any more recent date comparatively small, and, with one or two exceptions, I than that of the uplift of the northerly trap hills. have invariably been able to establish some connection between the native metal occupying these joints and the Veins clearly of a date posterior to the uplift of that termination of some metalliferous vein that traverses portion of the trap rock last mentioned, are of frequent other portions of the rock not far distant, and it is occurrence, and these veins not only traverse a portion believed that the metal filling these joints has invariably Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 16 of 59 resulted from the action of causes precisely analagous the immense numbers of primary bowlders scattered over the southern to those which have placed similar metals in the veins to peninsula of Michigan indications of the existence of primary rock in place, in the district where they are found. which I have alluded. since been found to be the termination of a vein that is The earliest as well as all travellers, who have visited the somewhat obscurely continued from the trap region. district of country under consideration, have not failed to While these examinations were sufficient to enable me make frequent allusion to the loose masses of native to draw the inference that the masses of native copper copper that have been occasionally found scattered over came chiefly, if not wholly, from the trap, and more rarely it, nor has any one failed to allude to the large bowlder or from those sedimentary rocks resting immediately upon loose mass of that metal, upon the Ontonagon river. it, it was supposed that this occurrence would follow the Almost invariably, the opinion has been expressed, from general law, and that it, together with the other ores of the frequent occurrence of these masses, that the metal the metal, would occur in greatest abundance near the must be abundant in the country. But, after all, the true line of junction of this rock, with the overlaying sources from which these masses had their origin, or the sedimentary rocks. Nothing, or at least very little, was relation which they held to the rocks of the district, would known of the true extent or range of the trap rocks, and appear never to have been understood; and all or nearly the very great inaccuracies in the published maps of the all that was known of their true relations, was left to country, rendered it almost impossible to apply even the conjecture. The result of this has been, that while some data on hand to such purpose as to relieve the have excessively magnified every thing connected with a embarrassment. subject of which, in truth, nothing was known, another class, equally far from what is really true, have regarded With a full knowledge of these difficulties, I determined, these masses of native copper as bowlders transported during the past season, to endeavor to surmount them from high northern latitudes.* by so far adding to our geographical knowledge of the coast of the lake and its immediate vicinity as to enable As far back as 1831 and 1832, I had occasion to pass, me to place whatever geological observations of no less than three times, along the south coast of Lake importance might be made in such condition that the Superior, as also to ascend several of the important relations of the several parts might be understood. tributaries of that lake, and during these years, I passed Having sufficiently accomplished this, I proceeded to a by three different routes, widely separated from each very minute examination of the several rocks overlaying other, completely across to the Mississippi river. It is or resting against the trap, together with a determination true that these journies, made through a complete of the thickness of the several members and their rate of wilderness, uninhabited except by savages, were decrease or wedging to the east. With these data I was necessarily made under circumstances that admitted of enabled, by noting the dip of the rock upon the coast, to only very general observations; but the result of these determine, with sufficient accuracy for the purposes to previous examinations have proved of immense service which the rule was to be applied, the line of junction to me, in aiding the labors of the past season. I allude to between the trap and conglomerate rocks. This rule, these journies and examinations at this time, in order to when put in practice, enabled me to decide, with a very show you the difficulties by which a full understanding of considerable degree of certainty, this line of junction, the subject under consideration is surrounded, for I when the rocks were covered with a very considerable became satisfied at that time, not only that the subject thickness of detrital matter, and when so covered, I was was not understood by the mass of those who had enabled, by traversing the country, on the line of bearing traversed the country, but that even the natives of the of the upper rocks, the more readily to gain access to country had no knowledge of the true sources from such points as would admit of examination. which the transported masses of copper had their origin. These observations soon showed me that this line of During the time of the examinations referred to, a bare junction between the trap rock, arid the south edge of glimmer of light was thrown upon the subject by an the conglomerate, instead of pursuing a course parallel examination of some small masses of, copper, found to the coast, only continued its parallelism for a few occupying the joints of the greenstone; as also by the miles westerly from the extremity of Keweenaw point examination of a single vein in the conglomerate, after which, for a long distance, it recedes from the coast containing the ores of copper, which has rapidly. These facts served to explain in part, why the *The vast area of country over which the bowlders of native copper, subject of the origin of the masses of copper had from the district under consideration, together with its westerly remained a mystery, for the country through which this prolongation,) have been transported, is worthy of remark. They are not of unfrequent occurrence in the sand and gravel of the southern line passes is hardly ever passed over, even by the peninsula of Michigan, and since the commencement of the geological Indians, and probably large portions of it have never survey, many of these masses have been met, some of which weigh been passed over by whites, but in addition to this, the from seven to eight pounds. In the vicinity of Green bay, a mass was obscure character of the metalliferous veins is such that discovered, some ten years ago, which weighed 140 pounds, if my memory serves me correctly. Loose masses of a similar character they would scarcely attract the observation of the have been met with in various other portions of Wisconsin, as also at traveller whose attention was not called especially to the various points in Illinois, Indiana and Ohio. In these eases, the subject, for many of the richest ores are so far from occurrence of these masses of native copper are no more indications having the appearance of the pure metal that they would of the existence of veins of the metal in the immediate vicinity, than are be the last suspected to contain it in any form. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 17 of 59 That the connection of these ores with the containing contents of the vein undergoes essential change, and rocks was not understood by the English mining not only does the vein appear to be influenced in its company, whose attention was turned to this subject, at mineral contents, but also in its width, for, as a general an early day, is to be inferred from the fact that they rule, the width of the vein increases as we proceed commenced their operations at Miners’ river, where the northerly, or from the greenstone. Thus, a vein which rock is the upper or grey sandstone, which has never may appear of only a few inches in width, or as a bare been observed to contain mineral veins; and also on line in the southerly or greenstone portion of the range, Ontonagon river, near the mass of native copper, at increases in width rapidly as it approaches and passes which point a shaft was commenced and carried about across the amygdaloid, and at or near the line of junction 40 feet through a reddish clay, at which point the red between the amygdaloid and the sedimentary rocks it sandrock was reached. Now, although the metalliferous will frequently be found to have attained a thickness of veins sometimes pass from the trap across the red several feet, while in its passage across the sedimentary sandstone, these veins in the red sandrock have never rocks it is usually either still further increased in width, or been noticed to contain any other ores than those of zinc becomes so blended with the rock itself, as to render it and iron, unless it be at the immediate point where the difficult to define its boundaries. vein crossing comes in contact with a dyke of trap, which These metalliferous veins, like those which occur under condition does not exist at the point alluded to, on similar circumstances in other portions of the globe, do Ontonagon river. What indications could have induced not continue uninterruptedly of any given width, for great these Quixotic trials at the points where they were distances, nor is their width increased regularly, for they commenced, is more than I have been able to divine, frequently ramify or branch off in strings, that pursue a and as might have been anticipated, the attempts course generally somewhat parallel to the general resulted in a failure to find the object sought. direction of the main vein, and which eventually again Having thus, in a general manner, set forth the obscurity unite with it. Sometimes these ramifications or branches by which the subject of the true source of the transported destroy, as it were, for a considerable distance, the masses of native copper has been surrounded, together whole vein; but they at length unite again, and the main with some of the reasons which have served to prevent vein is, after their junction, as perfectly developed as its being fairly understood, I will now proceed to a before. general sketch of the metalliferous veins of the district, While traversing the most compact, southerly portions of so far as the same have been examined; premising, that the greenstone, the veins are most frequently made up our knowledge of them is still deficient in very many of a very compact and finely granulated greenstone, important particulars, which can only be supplied by a sometimes associated with steatitic minerals and silicate careful and continued examination of the subject, which, of iron, under which circumstances they usually are in fact, can only be said to be but just commenced. destitute of any other metallic mineral, but occasionally, I have had occasion to refer to the outer or northerly instead of the materials above mentioned, their place is range of hills, or those from which the metalliferous veins supplied by native copper, without vein stone or matrix, may be said to spring, as being composed of trap rock, and usually free from nearly all earthly impurities, but and lest what has been said may not be fairly almost invariably incrusted with oxid, or carbonate of the understood, I will repeat, that the more southerly part of metal. Those portions of the vein traversing the the range is uniformly composed of compact greenstone, greenstone, in which native copper occurs, under the under which head I not only include true greenstone, but circumstances above mentioned, are invariably thin, also those forms of altered granular gneiss and rarely exceeding 3 to 4 inches in thickness, and usually gneissoid granite, which sometimes are associated with considerably less, and they are liable to very it, while the outer or northerly portion of the same range considerable variation in width, from the divergence is usually composed of an amygdaloidal form of trap. caused by the vein traversing the joints of the rock, The cells of the amygdaloid are usually filled with the where these joints produce the same character of different varieties of quartz, carnelian, chalcedony and change as is produced by the ordinary ramification of a agate, and sometimes, though more rarely, with native vein. copper, or with calcareous spar, though they are As these metalliferous veins traverse the northerly sometimes entirely empty, constituting a perfect portion of the range, or approach the sedimentary rocks, toadstone. they undergo a gradual change in width as well as in The metalliferous veins cross this range of trap, usually mineral character, and it has been noticed that where very nearly at right angles to the prolongation of the hills, the amygdaloid is most largely developed, the vein, as a and are frequently continued in the same course, across general rule, has not only a greater width, but also has the upper or sedimentary rocks, thus crossing the latter its mineral contents more perfectly developed, a at an angle varying but little from their line of bearing. circumstance which might fairly have been inferred from While the continuity, of course, of the vein, may remain the fact that those points where the amygdaloid occurs perfect in its complete passage from the greenstone most largely, may be regarded to have been so many across the several members of the conglomerate, mixed centres of intensity of action, at the time of the original and red sandstone rocks, the character and mineral uplift of the range, from which circumstance they would

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 18 of 59 remain in a softened state, or in such condition as to very greatly in width, ranging from a mere line to 14 or admit of the more perfect formation of these cross veins 15 feet, the greatest observed width of any single vein. for a longer space of time after that condition had been In the descriptions of the veins given above, I only intend passed at other points. to include those which are most perfectly developed, for, In the outer or amygdaloid portion of the rock, the vein is in addition to these, there are also many which are almost invariably accompanied by a veinstone of quartz, imperfectly formed and short, and in which many of the involving all the varieties before mentioned, as above characters are in part or entirely wanting. These associated with the trap rocks, which quartz, though latter are usually of little practical importance, and thus occasionally it occurs massive, of several feet in width, far have been comparatively little examined. usually appears in the shape of a series of irregularly Of the metallic minerals occurring in those portions of ramifying and branching minor veins, that may be said to the true veins which traverse the trap rocks, together constitute the main vein. These subordinate veins of with that portion of the conglomerate immediately resting quartz, which may be stated as the true veinstone, vary upon or against the trap, by far the most important from a mere line to several inches in thickness, and in consist of the several ores of copper, with which iron the aggregate they may be said to constitute from one- occurs disseminated in the forms before described, and third to one-half the total thickness of the vein. In their occasionally, though very rarely, native silver has been branches and ramifications, they sometimes include detected, associated in the same vein. After as minute portions of the rock which they traverse, at other times an examination of the subject, as circumstances will they embrace imperfectly formed steatite, with silicate, permit, I am led to the conclusion, that the only ores of carbonate and red oxyd of iron,* and occasionally, the metallic minerals, occurring in those portions of the though more rarely, it is associated with carbonate of veins, which traverse the rocks last alluded to, which can lime, usually assuming the form of an opaque rhombic reasonably be hoped to be turned to practical account, spar. are those of copper. As the main vein traverses the conglomerate and In these portions of the veins, the metal referred to, overlaying rocks to, and including the red sandstone, occurs very frequently in the form of native copper, with these veins, as a general rule, undergo still farther which are associated the red oxyd, azure carbonate, changes, for very soon after entering the conglomerate, green carbonate, and more rarely what may be the veinstone changes from its quartzose character, and denominated copper black, and still more rarely, pyritous is made up, either wholly, of calcareous matter, mostly copper. None of these have been noticed in a crystaline rhomb spar, or of this mineral with occasional form. ramifications of quartz. The whole usually including, and sometimes investing fragments of the conglomerate or It must not be imagined that these several minerals the pebbles of that rock, separated. make up the whole or even any very considerable portion of the entire length and breadth of the veins, in As the vein is continued still farther in the direction of which they occur, for they are distributed in bunches, and into the red sandstone, these changes are still strings, and comparatively narrow subveins, in a manner noticed, and precisely analagous to that in which these ores are *The latter closely resembling the Gosgan, of the Cornish miners. usually distributed, in similar rocks, in other portions of the globe. The quartz veinstone, before described, has eventually the vein is found to be composed either always so much of the green tinge communicated by the entirely or mostly of calcareous spar, and eventually so carbonate of copper, that it cannot fail to be detected; completely is its metalliferous character lost, that it would but the presence of disseminated native copper, in this not, if examined singly, be suspected to be any portion veinstone, would, at first, hardly be suspected, and it is of a metalliferous vein. not until a fresh fracture has been made, and the mineral The metalliferous character of these veins is most closely examined, that the numerous dark points and largely developed almost directly at or near to the line of minute threads are discovered to be copper in a native junction of the trap and sedimentary rocks, and they state. Large portions of this quartz veinstone, (when the rarely continue, without considerable change, for a included metal can scarcely be detected by the naked greater distance than one fourth to one-third of a mile, eye,) when examined with a glass, are found to contain on either side of the line, though a few veins were very delicate threads of native copper, that traverse the noticed in which in the southerly or trap extension, the quartz in every possible direction, and so completely is character of the vein continued for a distance of over a this latter mineral bound together, that it is fractured with mile, nearly unchanged, while in its passage through the difficulty, and its toughness is very greatly increased. conglomerate, for half that distance, its character was The specific gravity of this veinstone is very considerably also perfectly preserved. above that of ordinary quartz, and usually, the difference The mineral character of the veins is somewhat varied in is so considerable, even in those masses where the those having different degrees of thickness, though it is copper can scarcely be detected by the naked eye, as to difficult, if not impossible, to lay down any rule which be apparent to even the most careless observer. But in would characterize this change. The different veins vary addition to this finely disseminated condition of the

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 19 of 59 native copper in the veinstone, it is also disseminated in supplied by a variety of complex compounds of the same a similar manner through the rocky matter embraced by metal, which compounds are of exceeding interest; but the veinstone and in the amygdaloid and conglomerate this change would appear always to be intimately portions of the rocks, it sometimes extends, for a connected with, or to bear some relation to, the dykes of distance of from two to three feet into the rocky matter trap which traverse the conglomerate rock. Several on either side of the veins, sometimes completely, or in instances of this kind were noticed upon the northerly part, filling the cells of the amygdaloid rock. side of Keweenaw point, either directly upon or near to the coast, as also at several other places in the interior, The conditions above described refer to the main westerly from Keweenaw point. A vein, which may portions of the veins only, while there are other portions without doubt be referred to as one of this character, in which the copper appears to be concentrated in larger (though in consequence of intervening bays and lakes masses, constituting bunches and strings, and in which between it and the ranges to the south, its connection places the sides or walls of the veins are sometimes with the main range has not been seen,) will serve to wholly made up of thin plates of native copper. In these illustrate the character referred to. portions of the metalliferous veins where the metal appears, as it were, to be concentrated, it also occurs, This vein, which reaches the immediate coast of the much in the form before described, except that the lake, upon the easterly cape of the bay known to the masses of metal vary from the merest speck to that of voyageurs as the Grande Marrais of Keweenaw point, several pounds weight. In opening one of these veins, terminates, so far as examinations can be made, in the at a concentrated point, the observer, unless he had coarse conglomerate rock. The coast of the lake, for previously examined other portions of the vein, would be many miles on either side, is made up of abrupt cliffs of led to erroneous conclusions as to its richness, a source a similar rock, the rock as usual, being made up of of error which cannot be too strongly guarded against; coarse rolled pebbles of trap, chiefly cemented with for while the vein, for a short distance, may be found to calcareous matter, which is usually associated, more or be exceedingly rich in mineral, the mineral in another less, with the red oxyd of iron. Immediately south of the portion of the vein may either wholly or in part disappear, coast, a heavy dyke of trap traverses the conglomerate, a condition which is similar to that observed in those which dyke corresponds in position with line of bearing veins of copper that have been extensively worked and and dip of the conglomerate rock. found to be most productive, on the continent of Europe The vein, which, at its termination upon the immediate and the island of Great Britain. coast of the lake, has an extreme width of about 10 feet, The excess of native copper, (compared with the other may be traced, in the bed of the lake, in a direction north ores,) which occurs, in these portions of the veins, is a 5° east, for a distance of several rods, after which, in peculiar feature, for it may be said, in truth, that other consequence of the depth of water, it is completely lost. ores are of rare occurrence. In those portions of the This vein, at the point where it appears upon the coast, veins traversing the trap, and where other ores do occur, may be said to be in a concentrated state, or in a it is usually under such circumstances as to favor the condition analagous to that before described, where the presumption that their origin is chiefly from that which native copper occurs in the condition of bunches and was previously in a native form; for the carbonates and strings, though the condition in which the metallic oxyds, almost invariably appear either investing the minerals occur, is essentially different from that in the native copper, or intimately associated with it, though trap; for, instead of native copper, we have several they sometimes appear in distinct sub-veins. Pyritous mixed forms of the green and blue carbonates of copper copper is so rare, in connection with the trappean and copper black, more or less intimately associated portions of the veins, as scarcely to deserve notice. with calcareous spar, and in the adjoining rock, and in small ramifying veins, occasional small specks and I have already stated that native silver, occasionally, masses of native copper, weighing from 1 to 3 oz., though very rarely, occurs in the trappean portions of occur, but these are by no means abundant. No quartz these veins, intimately associated with the copper, but it occurs as a veinstone, and none of the ores have been is in so minute quantities as to render it probable that it noticed in a crystaline form. will not prove of any practical importance. Other mixed compounds of this metal occur so rarely as scarcely to It has already been stated, that these true veins, in deserve notice. traversing the conglomerate, frequently almost loose their character, and it becomes difficult to define their Leaving the trap rock, the character of these veins, as absolute width, or in other words, it would appear as if, they traverse the conglomerate, undergoes important at the time of the formation of the veins, the changes; for not only does the veinstone become conglomerate had not been perfectly cemented, the gradually changed, from quartz to calcareous spar, but result of which would be, that the mineral matter, which, the amount of native copper diminishes, and its place is under other circumstances, would constitute a perfect either supplied wholly or in part by ores of zinc and vein, would frequently appear in only an imperfect one, calcareous spar, or wholly by this latter mineral. There or the mineral which would, under other circumstances, are, however, occasional exceptions to this general rule, make up the vein itself, may have been injected laterally for occasionally the place of the native copper in the through the interstices of the rolled masses constituting veins, in their passage through the conglomerate, is Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 20 of 59 the conglomerate, in which case the mineral would, in noticed of Isle Royale, that the veins, so far as fact, take the place of the ordinary cement, thus simply examined, are less perfectly developed in their passage investing the pebbles of the conglomerate. Now, across the conglomerate, and that they very rarely although at the point under consideration, a wide and contain any traces of zinc. remarkably distinct vein is developed, the rock, for many Upon the north shore of the lake, no attention was given feet on either side, has the interstices between the to the subject of mineral veins, but from the character of pebbles filled wholly, or in part, with various mixed and the geology of that district, it maybe inferred that they will irregular forms of the ores, accompanied by calcareous also be found in portions of it, and that, where they do matter, as before stated, and with occasional specks and occur, they will be uniformly either directly upon or not small masses of native copper. far from the coast of the lake. Those veins traversing the conglomerate take on a In addition to the regular veins already described, similar character, to a greater or less extent, rather irregular veins frequently occur, traversing the whole, or frequently, but the place of the copper is more usually portions, of the outliers of trap, or those knobs which supplied by the siliceous oxyd, and more rarely by the appear to have been elevated singly; and although these carbonate of zinc, which compounds, sometimes may be veins may without doubt, be referred to the same epoch seen forming a perfect or partial cement to the rock, for as the regular veins before described, they nevertheless considerable distances on either side of the main vein. frequently differ considerably in mineral contents. These ores of zinc, like those of copper, are uniformly amorphous, and almost invariably more or less The limits of the present report will not permit a separate associated with some form of carbonate of lime, with description of these several distinct trap knobs. I will which they may, under some circumstances, unless therefore confine my remarks to that already referred to, closely examined, be confounded. as occurring upon the south coast of Lake Superior, immediate northwest from Riviere Des Morts, and which Although these copper and zinc ores occasionally forms the promontory known m Presque Isle. appear in considerable quantities, in those portion of the veins traversing the conglomerate, they usually embrace In nearly all those portions of this knob, where the trap, or simply encrust portions of the rocky matter; or rather conglomerate and sandstone, are exposed in such a the rocky matter and those ores appear to be coarsely manner as to permit examination, each of the rocks are and mechanically mixed. These veins furnish beautiful seen to be traversed by innumerable irregular ramifying cabinet specimens of the blue and green carbonates of veins, which in the sandstones are made up of copper, and more rarely of pyritous copper, together with quartzose and calcareous matter; but many of which, the other varieties mentioned. near the junction of the igneous and sedimentary rocks, are metalliferous, and this metalliferous character is Having already devoted a larger space to the more fully developed as the veins are extended into the consideration of these veins than had been intended, I trap rock. will simply add, that in pursuing their course northerly, across the mixed rock and the red sandrock, their The metalliferous portion of these veins, rarely exceed mineral character is nearly or quite lost, the veins as three to four inches in width, and they ramify in such a before stated, being made up either entirely of manner that the mineral uniformly occupies situations calcareous spar or of that material containing very similar to bunches or strings, at the junction of the meagre ores or zinc. ramifications. The minerals contained in the metalliferous portions of the veins, are sulphuret and The district of country to which these veins have been carbonate of lead, earthy, green carbonate of copper, referred, thus far, only comprises the ranges of hills pyritous iron, and more rarely, pyritous copper. south of Lake Superior, but veins of a very similar Occasionally there is a quartzose, or mixed quartzose character, and of similar mineral contents, also occur and calcareous veinstone; but more usually the several upon Isle Royale. The order and changes in the metallic minerals are blended in a base of rocky matter. character of the veins upon Isle Royale is necessarily The sulphuret of lead is distributed in the form of small reversed, or in other words, the southerly point of the cubic crystals, while the other metallic minerals are vein corresponds to that of the north point in the district usually distributed either in irregular masses, or investing south of Lake Superior. The mineral veins of Isle Royale portions of the rocky matter. These associations are have not been examined with sufficient care to enable referred to, as showing the character which these me to determine with much certainty, their average width irregular veins assume, rather than from any supposed or value. Those examined were mostly narrow, the value which they may possess for practical purposes. widest not exceeding eighteen inches, but in these the mineral contents are essentially the same as in those In addition to the minerals referred to, the trap of upon the south side of the lake. Presque Isle occasionally contains asbestus, common serpentine and imperfect agates; the two former Native copper, in very thin plates, was occasionally minerals usually occupying the narrow joints of the rock. noticed, occupying irregularly the joints of the compact greenstone of Isle Royale, but invariably in Before referring to the economical considerations comparatively small quantities. It should, however, be connected with the veins which have been described, I

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 21 of 59 will briefly refer to another situation in which the ores of examination of a few points, to attempt to determine the copper have been observed in intimate connection with character of the whole. the trap range of rocks. In considering the practical value of the copper ores of The southerly side, or greenstone portion of the trap the upper peninsula of Michigan, where we are as yet range, appears to have been elevated in such a manner compelled to judge from our examination, of what may as to have caused but little disturbance to the sandrock be said to be the simply superficial portions of the veins, lying between that and the range of simply altered rocks we can arrive at no safe conclusions, except by lying still farther to the south; but near to the junction of comparison of the district with those districts similarly the sandrock and greenstone there is usually a red slate situated, which have been extensively worked in other resting against the trap, and which may be said to fill up, portions of the globe. Comparisons of this character, to in a measure, the irregularities in the ranges of hills. be really useful, must necessarily be sufficiently minute This slate, which is sometimes seen of 100 to 200 feet in to enable us to understand the relations which the ores thickness, though usually it appears as a mere band, is in the districts compared, bear to each other, in all traversed by irregular and imperfect veins, of what may respects, which circumstances renders it necessary that be denominated a ferruginous steatite, containing a degree of minute information should be at hand, that is placentiform masses of greasy and milkish quartz, that not at all times to be obtained. As the information on sometimes contain more or less of the ores of copper. hand, with respect to the copper and tin veins of The earthy carbonates of copper are also sometimes so Cornwall, England, is more minute than that of any intimately connected with these veins of steatitac matter mineral district known, I propose, in order to avoid as at first to be scarcely recognized. More rarely, confusion, to confine my comparison to this district, distinct, very thin veins of green carbonate of copper simply, premising that however closely the two districts occurs, well characterized, in this red slate, though these may resemble each other in character, it does not follow, veins are never of any great length. The red shale as an axiom, that because the district with which we extends, more or less perfectly, along the whole length compare our own has been largely and profitably of the trap range, skirting that range of hills upon the productive, that of Michigan must necessarily be so too, south, but I have not yet been enabled to devote for it will be seen, as the subject is pursued, that there sufficient time to its examination to enable me to are not only several points in which it is impossible with determine whether any portions of these veins can be our present knowledge of that of Michigan, to institute regarded as of practical importance. The examinations comparisons, but there are also some points on which which have been made would lead me to look there is a considerable degree of discrepency. unfavorably upon these veins, and I regard them as The comparison instituted, in the main, is intended to having an origin completely distinct from that of the veins refer rather to the character and contents of the mineral which traverse the northerly escarpment of the trap rock. veins of the two districts than to the geology, although Having thus considered all the general circumstances some general reference becomes necessary to the under which the several ores of copper, zinc, lead, iron, geology of the districts, to render the comparison manganese and silver have been noticed, in connection perfect. The topography of the Cornish district bears a with the trap rock and the sedimentary rocks, close resemblance to that of Michigan, both districts immediately resting upon it, it becomes important to being marked by their irregular and broken outline, and consider how far inferences may be drawn from these by the occurrence of more or less frequent, nearly examinations, as to their occurrence in such quantities insulated knobs, rising to a considerable height above as to be of practical importance. I have already stated the elevation of the general ranges. that so far as regards the ores of lead, iron, manganese Although the older rock of Cornwall, or that from which and silver, I am led to conclude that at none of the points the metalliferous veins of the district may be said to have examined do they occur in veins, or otherwise, their origin, is more distinctly granitic than that of the sufficiently developed to warrant favorable conclusions metalliferous region upon Lake Superior, the elements of as to their existence in sufficient quantities to be made which the rocks are composed, may be regarded as available, and from all that is now known of the country, I essentially bearing a very close resemblance; a am led to infer that neither of these, unless it be iron, will resemblance which, it is conceived, would have been be so found.* still more perfect had the granitic rocks of Cornwall been The examinations which have thus far been made of subjected to the action of secondary causes similar to those portions of the veins containing ores of zinc, have those of the region under consideration. The rocks not been extended sufficiently to enable me to determine resting upon or against the granitic rocks of Cornwall, with much satis- consist of clay slates, hornblende rocks, &c, which bear little real analogy to the rocks resting directly upon the *These remarks are intended to apply directly to the trap region. Beds of bog iron ore occur, east from Chocolate river, which probably may at trap of Lake Superior, but it is conceived that the some future day be profitably worked. composition of these upper rocks has little bearing upon the origin of the metalliferous veins, and may be faction, their extent as a whole. At several points in the regarded as in a measure unimportant; and however veins these ores are sufficiently abundant to admit of much these rocks may differ, they are traversed alike by being profitably worked, but I would be unwilling, from an Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 22 of 59 the metalliferous veins of the lower rocks in such a with its associations, so universal, that when applied to manner, that the close resemblance cannot be mistaken. this mineral, they may be regarded as general laws, that may fairly be inferred to govern, with more or less It is a matter of history that the ores of tin have been, certainty, all those lodes or veins which have similar more or less, extensively raised in the mineral district of geological relations. Though a general consideration of Cornwall, from the earliest settlement of the island of those relations of the veins of other countries, may Great Britain, but the working of the veins of copper at perhaps be regarded as somewhat foreign to the present an early day, does not appear to have been carried on to report, I deem it more advisable to refer to these general any very considerable extent. The great importance to laws in such a manner as to leave the reader to judge, which the produce of copper from the Cornish veins, (in by comparison, the condition in which the ores of a district which, compared with the mineral district of our Michigan may be fairly inferred to occur, rather than to own state, is of very small dimensions,) has arisen, will draw conclusions directly; and in so doing, it will also be shown from the accompanying table, which I have become necessary to refer to some of the characters of reduced from the official returns, included in the several mineral veins, or lodes, in general. years, and which table, it will be seen, shows for a series of years, the average annual amount of copper produced Veins are usually divided into two general orders, viz: from the ore, the average amount for which it sold, “cotemporaneous veins, or those which were formed at together with the amount percent of copper contained in the same time as the containing rock, and true veins, the ore, and the average value of the copper, per pound, whose formation is supposed to be subsequent to that of at the smelting house. This table, which has been drawn the rooks which are contiguous to them.” A true vein with great care, from data that can scarcely lead to may be defined to be the mineral contents of a vertical or incorrect results, will not only serve to show the large inclined fissure, nearly straight, and of indefinite length aggregate amount of the metal produced, but it also and depth.”* The contents of a true vein, as a general shows, from the low average per cent of metal contained rule, differ widely from the character of the rocks which it in the ores, (if we had no further knowledge upon the intersects, though this does not invariably hold good, subject,) that much capital must be required for, and a and the vein also, as a general rule, has well defined large amount of labor applied to the raising and smelting walls. of these ores; a circumstance which should be carefully The contents of contemporaneous veins, bear a much borne in mind, in all that relates to the mineral district of closer resemblance to the rocks which embrace them, Michigan. and as a general rule, they are shorter, more crooked, and less perfectly defined than true veins. The metalliferous veins being contained under the head of true veins, it is to these that the whole of my remarks will be directed. Metallic veins are the repositories of most of the metals excepting iron, manganese and chrome, which occur more frequently and abundantly in beds than in veins. The thickness of metallic veins varies from a few inches to many feet, and the same vein also varies in thickness in different parts of its course, sometimes contracting to a narrow string of ore, and then expanding again to a The general resemblance in the mineral contents of the width of many feet. The deposits of metal in the veins copper veins of Cornwall and those of Michigan, is for are as irregular as the widths of them, and so much so the most part very great, though in some respects there as to render the profits of mining proverbially uncertain. is a considerable discrepancy. It should, however, be Ore is generally found to occupy certain portions of the remarked that some difficulty exists in comparing the veins only, differing constantly in extent, whether the mineral veins of Cornwall, where several of them have length or depth on the course of the vein be considered, been worked to depths, varying from 1,000 to 1,500 feet, or the portion of its width which is filled up by it. No with those of Michigan, where the examinations are veins occur which are regularly impregnated with metal nearly superficial. to any great extent, and when ore is found, it is in what the miners aptly term bunches or shoots, or in In making these deep excavations, not only in the county interspersed grains and strings, which are more or less of Cornwall, but also in the copper districts of Bohemia, connected with, or embraced in, veinstone, that, Hungary, Silesia, Transylvania, Saxony, &c, (some of according to the rock which the veins intersect, will be the veins in the latter districts having been explored to a fluorspar, calcareous spar, quartz, &c. The unproductive depth very considerably greater than those of Cornwall,) parts of veins, even in the most profitable mines, an immense mass of facts has been accumulated, with generally far exceed in extent the productive parts, but respect to the general formation and mineral character of that mine is considered to be rich which has either veins, or lodes of copper, which facts have Jed to an frequent or extensive shoots of ore, and the great art of understanding of many of the contingencies connected the miner consists in tracing and working the valuable Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 23 of 59 accumulations of the metals, with as little waste of labor to examine, without undue expectations, those mineral and expense on the poor portions of the veins as veins which occur within the limits of our own state. In possible. “In the mines of Cornwall, the ores of copper the main, the resemblance between the character and and tin commonly occur in detached masses, which are contents of the copper veins of Cornwall and Michi called bunches of ore; and the other parts of the vein, *Koenig. being unproductive, are called deads.” †Lyell. Neeker. The depth to which metallic veins descend is unknown, for gan, so far as can be determined, is close; the veinstones, (with the exception of fluor, which I have *Carne, on the mineral veins of Cornwall never observed in the latter,) are essentially the same; we believe no instance has occurred of a considerable but in instituting this comparison, it should be borne in vein being worked out in depth, though it may sink too mind that the metallic veins of Cornwall have been in deep to render the operation of the miner profitable, or it progress of exploration for centuries, and that shafts and may branch off in a number of strings which are too galleries have been carried to great depths, while of much intermixed with the rock to be worked to those of Michigan, simply superficial examinations have advantage.* Some veins appear to grow wider, while as yet been made, and these in a wilderness country, others contract as they decend. under circumstances of the utmost embarrassment, and attended with the most excessive labor, privation and The superficial part of a vein generally contains the ore suffering. in a decomposing state, and it frequently happens that the ores in the upper and lower parts of a vein are In respect to the character of the ores which occur in the different; thus, “in Cornwall, blende or sulphuret of zinc two districts, there are important differences, for while often occupies the uppermost part of the vein, to which pyritous copper is the most important workable ore, not succeeds, tinstone, and at a greater depth, copper only in the Cornish mines, but also in those of other pyrites.” When a metallic vein, in its descent, passes portions of our globe, it is comparatively of rare through different kinds of rock, it is frequently observed occurrence in the mineral district of Upper Michigan; for, that the products of the vein vary in each bed, and when as I have already mentioned, the mineral of the trappean it passes through regularly stratified beds of the same portions of the veins in the latter district, is essentially rock, there are particular strata in which the vein is made up of strings, specks and bunches of native always found most productive. This change in the copper, with which more or less of the oxyds and productiveness of mineral veins is more particularly carbonates are associated; while those portions of the noticed at or near to the transition from unstratified to veins traversing the conglomerate are characterized by stratified rocks; thus granite, syenite and those rocks the occurrence of the oxyds and carbonates, with which have a granitiform structure, are frequently noticed occasional metallic and pyritous copper, or the places of to contain metals at or near their junction with stratified all these are supplied by ores of zinc, associated with formations. On the other hand, the veins which traverse more or less calcareous matter. In the thin mineral veins stratified rocks are, as a general law, more metalliferous of Presqne Isle, pyritous copper is more abundant, near such junctions, than in other portions.† where it is associated with sulphuret of lead, as before mentioned. Where a rock is crossed and penetrated by a great number of small veins in every direction, the whole mass The occurrence of this native copper in the veins, and is sometimes worked as an ore, and is called by the the manner in which it is associated with the veinstones, Germans a “stock-worke.” Where the ore is in all respects corresponds with the ordinary association disseminated in particles through the rock, such rocks of the other forms of ores, in those veins that have been are also worked for the ore, when it exists in sufficient extensively worked in other portions of the globe; but I quantity. confess that the preponderance of native to the other forms of copper, was regarded as an unfavorable As a general rule, those metals which are oxydable at indication, at least until this had been found to be more ordinary temperatures, or which readily combine with or less universal with respect to all the veins. It should, sulphur, rarely occur in a metallic state, but are usually however, be remarked, that in those portions of the veins found in combination either with sulphur, oxygen or where the quartz of the vein and the accompanying rock acids. The chief ore of copper raised from the mines of are very compact, the native form is much more Cornwall, is the yellow sulphuret, though the blue and common than in those portions where the veinstone and green carbonates and arseniate are more or less accompanying rock are more or less cellular and soft. distributed; native copper and the oxyds are also, though more rarely, found. The worked copper veins of Cornwall, are stated by Mr. Carne, to average from three to four feet in width, and to By a comparison of what has been said upon the have a length as yet undetermined. But few have been character and mineral contents of metallic veins in traced for a greater distance than one to one and half general, I trust a just view of the real condition in which miles, and but one has been traced for a distance of the ores of copper are invariably found, will have been three miles. conveyed, and that, by the aid of this, we will be enabled

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 24 of 59 The veins which I have examined in the mineral district The value of a vein may be said to depend upon the of Michigan, exceed the average of those last abundance of the ore, and the ease with which it can be mentioned, but the imperfect examinations which have raised and smelted, rather than upon its purity or been made, render it difficult to determine this with richness. Upon this point, with respect to our own certainty. I have traced no one vein for a further mineral region, public opinion would perhaps be more in distance than one mile, and usually for distances error than upon any other, and most certainly we could considerably less. It was not, however, supposed that hardly look for a mineral district where the character of these veins terminated at the points where they were the ores were more liable to disseminate and keep alive left, but the further examinations were abandoned at such errors. The occurrence of masses of native metal, these points, in consequence of physical difficulties either transported or in place, are liable to excite, with connected with the present condition of the country. those who have not reflected upon the subject, expectations which can never be realized, for while, in The native copper is frequently free from all foreign truth, the former show nothing but their own bare matter, and is as completely malleable as the most existence, the latter may be, as is frequently the case, perfectly refined copper, but it more usually contains simply imbedded masses, perfectly separated from all disseminated particles of earthy minerals, chiefly quartz. other minerals, or they may be associated in a vein I have not been able to detect the alloy of any other where every comparison would lead to unfavorable metal, in a single instance. conclusions, as to the existence of copper, in any The fatigues and exposures of the past season, have so considerable quantities. I have frequently noticed very far impaired my health, that, as yet, I have been unable considerable masses of native copper, occupying the to analyze as carefully, as could have been wished, the joints of compact greenstone, under such circumstances several ores furnished by the mineral veins of the upper as I conceive, might readily excite in many minds, high peninsula, but sufficient has been done to show expectations, but a little reflection would satisfy the most satisfactorily that the copper ores are not only of superior careless observer of the uselessness of exploring these quality, but also that their associations are such as to joints, under the expectation or hope of finding them a render them easily reduced. Of those which have been valuable repository of the metal. Again, not only native, examined, embracing nearly the whole, (and not but also the other ores of copper occur in veins, either so including the native copper,) the per cent of pure metal, narrow as to render it useless to pursue them, or so ranges from 9.5 to 51.72, and the average may be associated as to render it probable that exploration stated at 21.10. Associated with some of these ores, I would not be attended with success. have detected a metal, the character of which remains, While I am fully satisfied that the mineral district of our as yet, undetermined. state will prove a source of eventual and steadily Were the analysis of the several ores of copper increasing wealth to our people, I cannot fail to have sufficiently perfected, I should deem it unnecessary to before me the fear that it may prove the ruin of hundreds lay them before you at this time, for with what is now of adventurers, who will visit it with expectations never to known of the district, it is conceived, the result would be realized. The true resources have as yet been but lead to erroneous, rather than to correct conclusions. little examined or developed, and even under the most The analysis of separate masses of ore, no matter how favorable circumstances, we cannot expect to see this much care may be taken to select the poor as well as done but by the most judicious and economical the richer ores, for the examinations, will usually be far expenditure of capital, at those points where the from giving the average per cent of what would be the prospects of success are most favorable. It has been product when reduced to practice. I have, in order to said of the Cornish district, in respect to the supposed arrive at safe conclusions, not only analyzed, but also large aggregate profits, that “a fair estimate of the assayed many of them, but when we come to consider expenditure and the return from all the mines that have what constitutes the true value of a vein of copper ore, been working for the last twenty or thirty years, if the we will perceive why it is unsafe to judge of the whole by necessary documents could be obtained from those who the analysis of small portions. are interested in withholding them, would dispel the delusion which prevails on this subject, as well as check By reference to the previous statistical table of the that ruinous spirit of gambling adventure which has been product of the copper mines of Cornwall, it will be seen, productive of so much misery.”* And if these remarks that the average produce of the ores since 1771, has will apply to a comparatively small district, which has never exceeded 12 per cent of the metal, and that from been explored and extensively worked for centuries, with 1818 to 1822, it was only 8.2. This shows the how much more aggregate, and it is well known that while many of the productive veins are considerably below this, the largest *Hawkins on the tin of Cornwall. average per cent of any single vein, in that district, it is force must they apply to the mineral district of our own believed, has never been over 20 per cent, and it should state. I would by no means desire to throw obstacles in be borne in mind that this average is taken after the ores the way of those who might wish to engage in the have been carefully freed from all the rocky and other business of mining this ore, at such time as our impurities, which can be separated by breaking and government may see fit to permit it, but I would simply picking. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 25 of 59 caution those persons who would engage in this trap, has already been noticed, and these minerals are business in the hope of accumulating wealth suddenly considerably abundant. They frequently possess very and without patient industry and capital, to look closely great beauty and perfection, and when ground and before the step is taken, which will most certainly end in polished, they may be used for all the purposes to which disappointment and ruin. those minerals are usually applied. The extreme length of what I have denominated the Minerals of the Upper or Gray Sandstone. mineral district, (within the limits of Michigan,) may be Though the upper sand rock is largely exposed along estimated at a fraction over 185 miles, and it has a width that portion of the lake coast known as the Pictured varying from one to six miles; but it must not be rocks, rising to a very considerable height in precipitous imagined that mineral veins occur equally through all cliffs, there have, nevertheless, been no minerals portions of it, for sometimes, for many miles together noticed in connection with it excepting iron pyrites. none have been noticed, and the situation of the country Along a portion of the distance, however, the rock of the is such as to render it probable they never will be. The cliffs is frequently colored by broad vertical bands, range and course of the mineral district has been so far having a variety of tints, (which have given name to this defined as to render it unnecessary to say more upon portion of the coast,) and these bands have been, by this subject, to enable such persons as may wish to some travellers, supposed to indicate the existence of examine, to pass directly along its complete length. important minerals in the rock; but the coloring matter of I have thus far omitted to allude particularly to the large these bands is merely superficial. It chiefly consists of mass of native copper, which has been so long known to the oxyd and carbonate of iron, with occasional feint exist in the bed of Ontonagon river, lest perhaps this traces of carbonate of copper, both having been isolated mass might be confounded with the products of deposited from waters while trickling down the cliffs, the the veins of the mineral district. That this mass has once same having previously percolated the rock. occupied a place in some of these veins is quite certain, No mineral veins have been noticed in connection with but it is now perfectly separated from its original this rock. connection, and appears simply as a loose transported bowlder. SOIL AND TIMBER OF THE UPPER PENINSULA. The attention of the earliest travelers was called to this mass of metallic copper by the natives of the country, The impressions which have gone abroad with respect and it has been repeatedly described by those who have to the character of this region for purposes of agriculture, visited it. The mass now lies in the bed of the westerly are, in many respects, exceedingly erroneous, for which fork of the Ontonagon river, at a distance which may be reason, I am the more solicitous to call attention to the estimated at 26 miles, by the stream, from its mouth. true character of the country, as it regards the natural The rugged character of the country is such, that it is but productions of its soil and its capabilities for cultivation. rarely visited, in proof of which I may state, that upon my It has generally been supposed that the whole country is visit to it, during the last year; I found broken chisels, wild and sterile in the extreme, and that, both from its where I had left them on a previous visit, nine years high northern latitude and the rugged and broken before, and even a mass of the copper, which at that character of its surface, it could never admit of the time had been partially detached, but which, for the want successful application of agriculture. This impression is, of sufficient implements, I was compelled to abandon, in great part, a mistaken one; for, while much of the was found, after that interval, in precisely the same country is, as has been supposed, extremely rugged, situation in which it had been left. often presenting a rocky and sterile surface, and is besides exposed to the long and bleak winters of a high The copper in this bowlder, is associated with rocky northern latitude, and to the cold winds of a vast and matter, which, in all respects, resembles that associated boisterous lake, yet, as I have already shown, a large with that metal in some portions of the veins before part of the upper peninsula is far from presenting a described, the rocky matter being bound together by rough and mountainous aspect; and much of the interior, innumerable strings of metal; but a very considerable at some distance from the lake shore, presents proportion of the whole is copper, in a state of purity. situations that are not only sheltered from the severity of The weight of copper is estimated at from 3 to 4 tons. the winters, but in soil and timber are wholly of a While the mass of native copper upon Ontonagon river different character from what has been represented. cannot fail to excite much interest, from its great size Much of the wrong impression which has been received, and purity, it must be borne in mind, that it is a perfectly with regard to the timber and agricultural character of the isolated mass, having no connection whatever with any country alluded to, has, no doubt, arisen from the other, nor does the character of the country lead to the circumstance that a judgment has been formed of the inference that veins of the metal occur in the immediate whole district of country, from the appearance of that vicinity, though, as before stated, the mineral district part of it which lies more immediately upon the lake crosses the country at a distance of but a few miles. shore; and in fact, were we to form our estimate of the The occurrence of carnelian, chalcedony, agate and whole, from that only which is seen by the voyageur, in amethystine quartz, in the amygdaloidal portion of the coasting along the shore, it would scarcely be possible Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 26 of 59 to form any other than a very unfavorable opinion of the soils may be said to be in general, rare throughout the value of the country, in an agricultural point of view. district under consideration. Beach and sugar maple are Along that portion of the district which lies upon Lake abundant throughout the portion of the district described, Superior, about one-third of the entire coast, westwardly mixed with hemlock and birch. from the Ste Marie, is generally low and sandy, and The hilly district, referred to as embracing the whole of thickly timbered with evergreens and white birch, which that portion of the upper peninsula which lies west of the give to it a somewhat gloomy and forbidding aspect. Still mouth of Chocolate river, though broken by ranges of further westerly, and extending to the extremely westerly knobby and often barren hills, is very far from being boundary of our state, the coast presents little else than wholly or even generally sterile; for the broad and gently an almost unbroken succession of rocks, bare, and worn undulating valleys, described as occupying the by the fury of the lake, and the country, as seen from the intervening spaces between these ranges of rocky water, appears to be occupied by an almost countless knobs, have in general a soil of dark, rich and deep succession of irregular knobs, either nearly destitute of loam, and in many places are covered with large bodies timber, or producing only a few stinted yellow pines and of sugar maples of unusual size. With this timber is firs, or a growth of worthless poplars; while the southern frequently intermixed oaks and large hemlocks, and shores of the upper peninsula, upon Lake Michigan and extensive bodies of the latter timber occur, together with Green Bay, though differing in character, present a occasional pines.* The streams of this district, where scarcely less forbidding aspect, in general, when viewed they wind through the bottom lands, between the ranges from the lake. But these unfavorable impressions are of hills which enclose the valleys, are frequently densely almost wholly, or in great part, removed when we wooded with all the varieties of hard wood timber, and penetrate into the interior, beyond these local influencing their banks exhibit deep alluvial loams, which, when causes, and become acquainted with the real condition once brought under proper cultivation, will be unexcelled and character of the districts described. for fertility even by the rich plains of our southern The general aspect of the surface, over the whole of the peninsula. These loams were sometimes observed to extensive district under consideration, has been already be underlaid by a red clay. As a whole, the soils of the laid before you, under the head of “topography of the hilly portion of the upper peninsula, may be said to be upper peninsula.” It may be remarked, in general, that generally superior to those of the extensive easterly sand is by far the predominating soil throughout the portion of the peninsula, and marshes are of a less entire district. A soil of this description prevails over the frequent occurrence. north-easterly or the sandstone portion, of the upper For purposes of lumber, the upper peninsula of our state peninsula. This district which, as has been already cannot be said to hold out such inducements as, from its described, consists of extensive level plateaus or situation, might be imagined. White pine, though steppes, with scarcely sufficient irregularities of surface sometimes met with in considerable quantity, was not in to prevent the formation of numerous marshes, may be any instance observed to have attained to more than said to be timbered, in the largest proportion, with the medium size, and is not generally abundant. The several varieties of evergreens, among which hemlock, Norway pine is found in much greater abundance and of cedar and firs greatly abound. Considerable Norway or fair size, but this species of pine is of comparatively little pitch pine is interspersed, with occasionally large white value, as an article of lumber. pines, though in limited quantity. This region, nevertheless, comprehends many extensive tracts of the FURS, FISH AND HARBORS OF LAKE SUPERIOR. sugar maple, lying in body, and these trees are In the general view I have attempted to give of the frequently of large size. Several species of oaks are character and resources of that portion of our state also occasionally met with. Upon the whole, much of bordering on Lake Superior, full justice cannot be done this portion of the peninsula is better adapted to the to the subject without adverting, however briefly, to the wants of settlers for agricultural purposes than might, at fur and fish trade of that upper country. first view, be supposed, and may be safely relied upon as capable of producing those crops which are of the It is well known that the American fur company has for a most importance to the settler. Wheat, in small quantity, long series of years, occupied posts, at convenient is said to have been raised upon Grand Island in a spot points upon the lake, as well as throughout the vast exposed to the utmost rigor of that northern climate, and territory of the northwest, for the trade with the natives in some species of Indian corn may, no doubt, be the furs of the country. Since the year 1835, the general successfully cultivated in the most sheltered situations. depot of the north-west trade in furs, has been The south-easterly portion of the upper peninsula, established at La Pointe, one of the Apostles’ Islands, embracing the lower limestone district, has a soil more near the western boundary line of upper Michigan, and nearly approaching to gravelly, and the pebbles in addition to this, other posts, of a more temporary and minor character, have from time to time, been occupied composing which are chiefly, derived from the northerly outcropping edges of the limerocks. This soil, in at various points, in the same region. These all formed consequence, contains much more calcareous matter parts, or, as it were, links of that extended and connected chain, with which this company had been than that above described, which adds greatly to its fertility. Clays occur to a very limited extent, and clay enabled to bind to its interests such an immense extent Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 27 of 59 of territory, and to draw into its storehouses those paid the Indians, which operates as a stimulus to treasures, in furs, with which this whole region originally industry, nor can we award too high praise to the bounded. The character of the company, its immense equitable course pursued by the company in this matter. resources, the perfect system that characterized its Lake Superior abounds in trout, white fish and Siskowit,* operations, as well as its distinguished success, are so the two former of which are larger and better flavored well known, and have so often been adverted to by than any that are taken in the more southern waters, and travellers and historians, that I allude to the subject here the latter fish has been rarely taken at any other station only for the sake of exhibiting more perfectly the present on the lakes; condition of upper Michigan, and to show what is the exent of the inducements held out to individual *An undescribed species of the genus Salmo. enterprise in that region. Nearly the whole of this trade is now, as it has been for a series of years, in the hands the consequences of which facts is, that the barrels of of the company referred to, and it has been secured to this company sell in the market at a higher rate than them by a course of judicious management, as well as those of the fisheries farther south; but, at the same by a large command of capital, and so powerful time, great disadvantage results to the company from continues to be the influence exerted by this company, the necessity of keeping vessels constantly upon the as to leave little chance of success to individual lake, for the express purpose of the fish trade, thus opposition, and the trade must continue to flow, mainly in greatly increasing the expenses and risks attending the its present channel. business. The trade in furs is, however, very far from being of that During the past season minor companies have been importance which it was formerly, for the amount of furs formed and have commenced the business of fishing has for many years past, been constantly diminishing, as upon this lake. Two vessels have been hauled around the country becomes exhausted of the game, and so the rapids at the Saut, for that purpose, and as the fish rapid has been the falling off, that at the present time the are abundant, there is a reasonable prospect that the amount of furs packed by the company, at this station, is fishing trade will eventually prove of great importance. scarcely half that which it was five years ago. At the But cut off as Lake Superior is, from direct same time, many important changes have been communication with the lower lakes, by an impassable introduced by the company in the manner of conducting rapid, this trade must continue to be carried on under the traffic; the system formerly pursued of granting great disadvantages, nor can the other resources of the credits to the natives on goods, sold at extravagant upper country be fully developed, so long as this barrier prices, a course not only unjust in itself, but destructive exists. The construction of the Saut Ste Marie canal, to habits of industry in the natives, has been entirely which has been long projected, but the necessity for abandoned; goods are now sold at moderate prices, which seems to be not yet fully appreciated, would anticipating only reasonable profits, and an equally fair remove this obstacle to the growing importance of that compensation is allowed for the furs. The company has, great region; and when this shall have been done, we furthermore, entered fully into the measures of the may expect to see all the resources of our upper government to prohibit the introduction of ardent spirits peninsula fully appreciated and made available. into the Indian country, and none is now employed in the trade; thus cutting off one of the chiefest sources of Directly connected with this subject, is that of the misery to the Indian population. I could not fail to notice harbors on the southern shore of Lake Superior; for that, since my last visit to the country, in 1832, the moral while such a field for enterprize is opened in that region, and social condition of the Indian population has greatly it is of essential importance to know what are the improved. This is owing, in great part, to the honorable facilities it affords for the safe navigation of the lake. Six and active measures adopted by the company, by which vessels are already navigating its waters, in the the means of subsistence among the Indians has been prosecution of the fur and fish trade, and although. much increased, many evils that formerly existed have hitherto, but few harbors have been known to exist, been removed, and an entire change has been brought which may be sought as places of refuge, the extreme about in their condition, and also to the exertions of the breadth of the lake does not fail to afford an several very excellent and worthy missionaries, who extraordinary facility in its navigation, by allowing a great have not only both by precept and example, been the extent of sea room, and thus enabling vessels, in case of means of introducing among them the meliorating storm, to “run before the wind.” influences of Christianity, but have laboriously devoted The harbor afforded by the group of Apostles’ Islands, their life to this “work and labor of love.” and which is taken advantage of by the American fur The American fur company also, at an early day, turned company at its present station, is deep and completely its attention to the fish of Lake Superior, and they have “landlocked,” and for safety and convenience could not since engaged largely in the business of fishing. Many be excelled. The same may be said of the natural half-breeds and Indians are employed in the business, harbor afforded by Grand island and the neighboring and this has also operated favorably upon the natives, shore. Both these harbors have long been known and and no doubt contributed largely to the improvement appreciated, and more convenient and safe retreats observable in their condition. Fair, if not high, wages are could not be wished for vessels driven by stress of Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 28 of 59 weather to “make a port;” nor could harbors be desired PROGRESS AND CONDITION OF THE affording greater conveniences for permanent stations. SURVEY, &c. I was enabled, during the past season, to effect a partial Notwithstanding the very many physical difficulties by triangular survey of several points upon the coast, which which the geological survey of the upper peninsula of seemed to promise advantages as harbors for vessels; our state is surrounded, we have, nevertheless, been and the depths of the water were uniformly taken, also, enabled to accomplish a much larger amount of the work at the mouths of streams. The result shows that, than reasonably could have been hoped; but there still although the number of places offering advantages for remains much to be done, before its geology and secure harbors is somewhat limited, along a part of the mineralogy can be fairly understood. Comparatively little coast, yet, that portion of the coast of our state lying has heretofore been known of the range and extent of upon Lake Superior, may be said to hold out as great the several rock formations, and, while the labor of the facilities, in this respect, as any equal extent of coast past season has shown the most interesting of these to upon the lakes. It might be supposed that Keweenaw have a much larger area than we had previously been point, from its extreme projection northerly, as well as led to infer; it has also shown, that the amount of work from the “rock-bound” character of its shores, would required, to enable us fairly to understand the geology serve to add to the dangers of the navigation, but along and mineralogy of that interesting region, was this rocky coast, are found occasional inlets into large considerably more than we had reason to look for. bays, stretching behind the extreme outer barrier of rock, and these are almost uniformly deep and completely The reports of the several assistants, will exhibit to you sheltered, and at some future time, may, with little or no the progress that has been made, during the past expense, be converted into a series of complete and season, in the surveys of the southern peninsula. permanent harbors. One of these bays or inlets, Messrs. B. Hubbard and C. C. Douglass were engaged distinguished on the maps as Copper Harbor, was with me, during the early part of the season, in the upper surveyed by a series of triangulations and soundings, peninsula; after which, they returned to carry forward the and was found to afford a bay, convenient for geological and topographical surveys of the lower anchorage, about two and a half miles in length, peninsula. I was also accompanied, during a small stretching parallel to the coast, and having a depth of portion of the season, by Mr. Frederick Hubbard, who from five to seven fathoms, and the entrance to which acted as special assistant, and who has embodied a has an uninterrupted breadth of three quarters of a mile, small part of his numerous observations in the form of a with a mean depth over the bar of twenty feet, and a report, which is hereto appended. maximum depth of thirty feet. These harbors, from their The survey of the lower peninsula is mainly completed, location with respect to the mineral district of the upper but there are some few spaces, both in the geological peninsula, as well as from the ease of access they will and topographical portions of the work, which require to allow to vessels which are exposed “off the point,” must be filled up before the results can be fully laid before the eventually become of very great importance. public. A natural harbor, of similar form to that above described, The drafting of the topographical portion of the survey, occurs upon a part of the coast east from the Pictured has advanced steadily towards completion, and the rocks, and in which the place of the cliffs of rock is several county maps are in progress of publication, in supplied by cliffs or spits of sand. The bay here formed, conformity to your instructions. behind the outer bar of sand and gravel, has a length of two miles, with an average depth exceeding six fathoms, While we had hoped to have been able to bring the and the water deepens so rapidly from the shore, that in survey to a close within the time originally contemplated, most parts of it a vessel of the largest draught may from the above statement of the progress and condition approach so closely to the beach as that a landing might of the work, it will be seen, that some further time will be be effected without aid from the boats. The entrance necessary for its final completion; but while this time will into this bay has a width of three-fourths of a mile, but a be essential to reach the object sought to be attained by bar of sand stretches across it, which would, at times, in our state, no farther appropriation will be necessary for its present condition, render the passage into the harbor that purpose. dangerous, for the average depth of water over this bar In closing this report. I feel it a pleasure to refer to the does not exceed six feet, though there is a depth in the very many acts of hospitality and kindness which have immediate channel, which is comparatively narrow, of been extended to us by the citizens of Mackinac, Saut ten feet. de Ste Marie, and La Pointe. By the aids received at Safe anchorage for vessels may also be found in these several places, we have been enabled to Keweenaw bay, a deep expanse of water, on the accomplish much that otherwise could not have been easterly side of Keweenaw point, and which stretches for done, while we have, at the same time, received much many miles inland. that has ministered to our comfort. To the agents of the American fur company in Lake Superior, I feel very deeply indebted; for, through their polite attentions, I have been enabled to examine Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 29 of 59 districts of country which otherwise could not have been Variation of the compass.—The results, in the subjoined reached, and to them and the several mission families, table, were deduced from a comparison of the observed are we indebted for all that it was within their power to magnetic azimuth of the sun with his true azimuth, as do^ to aid us in our laborious duties, or to render our calculated for the measured altitude and place of situation comfortable. observation. This method is one of great accuracy, and is almost the only one upon which dependence can be DOUGLASS HOUGHTON. placed, for results which shall not contain an error of State Geologist, more than two or three minutes, due to inaccuracy of observation. The angles were measured with a theodolite, containing a needle of great delicacy. A small correction to the table is necessary, on account Report of Frederick Hubbard, Special of the diurnal variation. This may amount to some 8’ or Assistant 10’, and possibly may be greater in some instances, when the observations were made during the warmest Utica, N. Y., November 20, 1840. seasons. As I have not the results of any experiments To DOUGLASS HOUGHTON, State Geologist: on this subject, now before me, I have thought proper to insert the date of each observation, and the hour of the DEAR SIR—I submit to you, the results of a portion of the day, that the correction may be made when the date can observations for the determination of latitudes, magnetic be obtained, with reference also to the metrological table variations, &c., made under your direction, during the kept during the survey. recent expedition of the state geological corps to the upper peninsula and southern shore of Lake Superior. By platting these variations upon the map of the coast, it will appear that there is a constant increase in the The subject of latitudes was made a matter of particular amount of deflection in passing westward, and at the attention, no regular survey ever having been made by same time that the increment is not in proportion to the the general government of that part of the lake lying westing, but is in a decreasing ratio, the distance within the boundary of our state. By means of between the lines, connecting the points of the same instruments, with which the expedition was furnished, variations, being greater as we recede from the line the positions of the most prominent points of the coast where the direction of the needle is due north. have been fixed by celestial observations, and with sufficient care to furnish, connected with the running From the observations in Riviere Ste Marie, it appears meander, an accurate outline. Unfortunately, we were that the line of no variation passes through that strait, not furnished with the proper instruments for the crossing Drummond Island near its western, and St. determination of longitudes. This problem, always one Joseph through its central or eastern part, with a course of great difficulty, for our purpose, would have required a about north by west. long series of the most careful observations, with the The determination of its exact position is a matter of most delicate chronometers, and a greater devotion of considerable importance, and I regret that circumstances time, than the circumstances of the expedition allowed. did not allow us, when in that vicinity, to spend more The ordinary lunar method, as practiced by navigators, is time in the investigation of this interesting subject. The not susceptible of sufficient accuracy to be of service in tracing of its supposed irregularities, and the a case of such nicety. ascertaining of the laws which, govern its changes, have Several rude attempts were made, however, with such for many years attracted the attention of the scientific means as we possessed, using a similar method, to fix world. the longitudes of a few points; but I do not place By marking upon the map the points of 1, 2, 3, &c, sufficient confidence in the results to deem it of degrees of variation, and drawing through them lines importance to lay them before you. parallel to the lines of no variation, it will be perceived The latitudes in the following table were mostly obtained that there are, in a few cases, important deviations from by measured altitudes of the sun, Jupiter and the polar the general regularity in which the deflections are found star. to increase. These differences are by far too great to be attributed either to errors in observation, to diurnal variation, or to the effect of atmospheric disturbing causes. I know not what influence the general topography of a country may have upon the directions of the magnetic needle, but it appears highly probable that something may be due to the outline of coast, to the unequal distribution of land and water, and to the influence of an open extent of sea, on the one hand, and of a mountain range upon the other. It might be suspected that these irregularities were the result of local attraction of metallic veins, or of some unknown

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 30 of 59 disturbances in the more immediate vicinity, did they not Report of C. C. Douglass, Assistant always occur where they seem to have an obvious connection with the circumstances I have mentioned. In Geologist. all these cases there is a deflection of the needle Detroit, January 4, 1841. towards the open lake, tending, when the land lies to the west of the place of observation to increase the amount To DOUGLASS HOUGHTON, State Geologist: of easterly variations, and the contrary. Thus we find, SIR—In conformity with your instructions, I have the about the Riviere des Morts, where the trend of the honor to report, that the examinations, assigned me to shore is northerly, at the several points to the east of the be performed in the northern portion of the southern Keweenaw peninsula, and at the village of La Pointe, peninsula, have been as nearly completed as lying to the eastward of a high range of hills upon the circumstances would permit. The duties performed mainland, a too great deflection towards the east, as if under your immediate directions, in the region of Lake the needle were actually effected by some repulsive Superior, delayed the commencement of this work until influence existing in the land, or a contrary principle, in the season was so far advanced as hardly to-allow the water. One or two instances occur, where the sufficient time for the completion of the unfinished work attraction is to the west, apparently from a similar cause. in this portion of the state. Whether this is the true explanation of the difficulty, I will In prosecuting the examinations in this district, I have not pretend to decide. The subject is one that merits made collections of duplicate specimens of all of the investigation, as having some bearing upon the science rocks, together with their contained minerals and of terrestial magnetism, many of whose principles are as characteristic fossils, all of which are deposited, yet enveloped in mystery. according to instructions, in the geological depot at Detroit, together with a transcript of my field notes. Previous to making these examinations, it had frequently been reported to me that coal had been found by the Indians and traders in the high lands lying east from the Traverse bays of Lake Michigan. These reports were soon shown to be without foundation, for the reason that the whole of the rocks of this district, lie below those of the coal formation.

Remarks on the general character of the NORTHERN PORTION OF THE LOWER PENINSULA. The country north of township nineteen north, and east of the meridian, is, on the whole, but ill adapted to the purpose of agriculture, being chiefly composed of sandy ridges, with intervening swales, and cedar swamps; many of the latter, however, are merely tracts of moist ground, covered with so dense a growth of white cedar as to be rendered almost impenetrable. The country rises so gradually towards the meridian of the state, as Accompanying this you will receive a map of the harbor to leave it generally flat and wet; but were the country of Grand Marrais and of Copper harbor, surveyed by cleared of its timber, and the water courses freed from your direction, while the geological corps were flood wood, much of the country would be rendered dry, encamped at those places. That of Grand Marrais is arable land. made, exhibiting only the general outline, a few points being fixed by triangulation, and soundings taken upon A large portion of the immediate shore of the lake, is low the bar at the entrance. Of Copper harbor a more land, either entirely or approaching to swamp. thorough survey was made; as complete as the limited High land was noticed lying at some distance back from time of our stay would permit. The outline of shore, the lake shore, between Presque Isle and the positions of reefs, &c, were accurately determined by a Cheboygan river, which belongs to, and forms a part of, system of triangulations, and soundings made across the chain of high land that appears on Lake Michigan, the entrance, and throughout the interior. A mere glance between Point Wabashance and Little Traverse bay. at the map is sufficient to show how little is left for art to do, to render this harbor one of the most secure places The greater part of the country, after passing west of the of refuge from storms, to be found in any part of the lake. meridian, is of a character very different from that just described, in point of soil, face of country, climate, &c. Respectfully, yours, F. HUBBARD. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 31 of 59 From old Fort Mackinac to the Manistee river, the land this, in some fine tracts of beech and maple, near the immediately upon the lake shore, and not unfrequently lake coast, also in the vicinity of some of the streams in extending back for many miles, is considerably elevated, the interior. and occasionally rises, very abruptly, to the height of It is nevertheless true that there are many extensive from one to three or four hundred feet. The country, swamps and marshes in this part of the peninsula; but it (more particularly, the northern portion,) continues to rise is to be doubted whether, upon the whole, they exceed as we proceed into the Interior, until it attains an in quantity or extent, those of the more southern part of elevation equal to, if not exceeding any other part of the the state. In point of soil and timber this portion of the peninsula. state is not inferior to the more southern, and such are This is more particularly the case in the rear of the the advantages it offers to the settler that, the day is not Traverse bays, where this elevation continues for many distant when it will be sought as a place of residence by miles into the interior, giving to the landscape a very the agriculturist. The beauty of its lakes and streams is picturesque appearance when viewed from some of the not any where surpassed. Such is the transparency of small lakes, which abound in this, as well as in the more their waters as to permit objects to be distinctly seen at southern portion of the state. the depth of more than thirty feet. The tract of country under consideration, is based on The small lakes abound in the finest of Mackinac trout, limestones, sandstones and shales which are covered, whitefish, sturgeon, pike, bass, sunfish, &c. The excepting at a few points, with a deposit of red clay and transparency of the water is so great, that the Indians sand, varying in thickness from a few inches to more are accustomed to spear fish where the depth exceeds than four hundred feet. thirty feet. The interior of the northern part of the peninsula, west of That part of the peninsula situated north of Grand river, the meridian, is generally more rolling than that on the is usually regarded by many of the inhabitants of the east. It is interspersed with some extensive cedar more southern part of our state, as being either an swamps and marshes, on the alluvial lands, and in the impenetrable swamp or a sandy barren waste, and as vicinity of the heads of the streams, and some of the possessing too rigorous a climate to admit of its lakes. The upland is generally rolling, has a soil of sand successful application to the purposes of agriculture. and clay loam, and is clad with evergreen timber, This is an erroneous opinion, and one which will most intermixed with tracts of beech and maple, varying in certainly be corrected as the facts with regard to this part extent from a few acres to several townships. of our state, come more fully to be known. The Some of the most extensive of these tracts are in the inhabitants of Flat Rogue, Maskegon and White rivers, vicinity of the Cheboygan and Tahweegan rivers, their and the Ottowa Indians, living on the Grand and Little lakes and tributary streams. There are also large tracts Traverse bays, and on the Manistee river, have of beech and maple timber lying between the head of extensive cultivated fields, which uniformly produce Grand Traverse bay, and the Manistee and Muskegon abundant crops. rivers. The country on Flat and Rogue rivers is generally rolling, The elevated portion of land on the shore of Lake interspersed with level and knobby tracts, but none is so Michigan, known as the “Sleeping Bear,” as well as the rough as to prevent its being successfully cultivated. Manitou islands, which, when viewed from a distance, The timber in the vicinity of the streams consists of have the appearance of sand, are found to be composed black, white and burr oak, which is scattering, and forms (excepting the recent sand dunes,) of alternating layers what is denominated openings and plains; small tracts of of highly marly clay and sand. The clay is of a deep red pine barrens, beech, maple and oak lands interspersed color, and in many places its strata are much contorted. with tracts of white pine. The hilly region to which allusions have been made, is Settlements are rapidly advancing in this part of our mostly heavily timbered with beech, maple, bass, oak, state, and much of the land under cultivation, produces ash, elm, birch, &c, interspersed with tracts of hemlock excellent crops of wheat, oats, corn, potatoes, &c, and and pine, and with an occasional cedar swamp. In the so far as experience has been brought to the test, is not vicinity of Grand Traverse bay, this character of country far inferior to, or more subject to early frosts in the fall extends into the interior for many miles bordering on a than the more southern counties of the state. series of small and beautiful lakes, which vary in length The soil varies from a light sand to a stiff clay loam. from two to eighteen miles, and are in general free from, marsh and swamp. This country, as also that in the The country on the Maskego is rolling, and may be interior, from Little Traverse bay, is well adapted to the considered as divided into beech and maple land, pine purposes of agriculture. lands, pine barrens, oak openings, plains, and prairies. Small tracts of the latter are situated near the forks of the Passing south of this rolling district, the country becomes river, about forty-five miles from its mouth, and between less elevated, and more variable, the soil assuming a thirty and thirty-five miles north of the rapids of Grand more sandy character, and being generally clad with river. Crops of corn, oats, wheat, &c, were here as evergreen timber. There are, however, exceptions to flourishing as those of the more southern part of the Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 32 of 59 state. Several families are settled on the prairies and It will be seen by referring to the above sections of the along the valley of the stream. They have two saw-mills rocks of Lakes Huron and Michigan, that the same in operation, one at the forks of the Maskego river, and rocks, with one or two exceptions, occur on both sides of the other on a small stream five miles below. the state, having the same geological position; also, that they have very nearly parallel and uniform positions. The soil of the prairies and openings is sandy, while that And from these out crops the rocks would appear to of the beech and maple lands is a sand and clay loam. have a bearing nearly north 70° west, and south 70° The Indians of Grand and Little Traverse bays and east, which line of bearing corresponds with the out crop vicinity, also obtain good crops of corn, potatoes, of the black bituminous slate on the east side of Lake squashes, &c. Some of the most intelligent Indians Huron in Upper Canada. informed me that their crops have never been known to ALLUVIUM. fail entirely, and that they were seldom injured by frosts in the fall or spring. They also have many apple trees Under this head may be included all those formations which produce fruit in considerable quantities. which are the result of causes now in operation. Such as beds of shells and tufaceous marls, deposition of silt This soil is strictly a “warm one,” and exposed as the at the mouths of streams, disintegration of rock strata, whole country bordering on Lake Michigan is to the growth of peat bog ores, &c. influence of the southern winds, during the summer, and parts of the spring and fall, it seldom fails to be Shell Marl productive. Is in general composed of small fresh water shells, chiefly univalve with occasional bivalve, which multiply, GENERAL GEOLOGY. most rapidly in shoal ponds or pools of water strongly For convenience of description, I will arrange the several impregnated with carbonate of lime. For the rock formations in groups, and beginning with those that accumulation of fresh water shells and shell marl, the occupy the highest place in the series, descend to the waters of the streams and small lakes of the northern lowest, or oldest rocks. Owing to the great accumulation part of the state, are well adapted. This marl has of superficial materials, which has prevented perfect accumulated in extensive deposits at the outlets and accuracy from being attained, these divisions may be inlets of most of the lakes on the Cheboygan, liable to modification upon subsequent and more minute Tahweegan and Pine rivers. There is, also, an extensive investigations. deposit of marl on the shore of Thunder bay, north of Thunder bay river. Tufaceous marl is also rapidly accumulating at the rapids of the streams above mentioned, where the deposition takes place in consequence of the water here being much agitated. The carbonate of lime precipitated at these points, is usually in the form of tufa, which readily adheres to whatever it comes in contact with, thus forming balls varying from one to twelve inches in diameter. Most of these balls have a shell as a nucleus. Tertiary and Boulders. Included in this division are alternating beds of red clay and sand which are nearly co-extensive with this part of the state. This formation overlays and rests un conform ably upon the lower rocks of the district, and in which respect, it corresponds, with the same formation in the more southern part of the state. It forms the base of most of the high banks of both Lakes Huron and Michigan, and is very finely exhibited at the Sleeping Bear, and on the Manitou islands of the latter lake. It also forms the base of most of the high knobs, in the interior of this section of the state. Most of this clay is very unctuous and nearly free from grit, but contains lime in sufficient quantity to injure it for the manufacture of brick. Primary boulders are very rarely met with on the upland; but those of a small size are very numerous on the shores of the small lakes, where there were also

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 33 of 59 numerous boulders of limestones seen associated with aspera and prisca, Delthyrus speciosa, Calamipora them. favosa, Orthis, Cyathophyllum ceratites, Orthocera, Calamapora favosa,

ROCKS OF LAKE HURON. BLUE LIMESTONE POINT AU GRES LIMESTONE. Limestone of a light blue color, and very compact, was This rock is, for the most part, of a light cream color, of a seen at intervals between Middle island and Forty mile compact structure, and will afford a tolerable building point, forming the bed of the lake, or but slightly elevated material. It contains numerous fossils. From this point above the water. It is regularly stratified and very north, on the lake shore, to Sulphur island, rock was compact, and contains numerous fossils; among those seen at intervals, forming the bed of the lakes which rock ascertained were the Atrypa prisca and aspera, Orthis, was referred to the sandstone formation. This space is Euomphaulus carinatus, Cyathophyllum helianthoides, undoubtedly occupied by sandstones and shales, the Flustra. equivalent of those on the coast of Lake Huron from MACKINAC LIMESTONE. Point aux Barques south, to White rock. In the vicinity of the Island of Mackinac, the upper Limestone of a very siliceous character occurs on the portion of this limestone is chiefly made up of broken Charity and other islands of Saginaw bay, where it was cemented fragments. The rock is of a light color, and seen in contact with, and overlying, the sandstone, and the fragments of which it is composed frequently occupies the same superposition as the limestone at the contains numberless minute cells. These were rapids of Grand river. undoubtedly once filled with spar, which has been washed out of the exposed part of the rock, by the action BLACK SHALE. of water. A black bituminous shale was first seen at Sulphur island, and also extending along the shore of the main Many of the more compact parts of this rock, when first land, for some distance. It is highly bituminous, burning broken, show numerous small veins of soar piercing it in freely when thrown upon the fire, and contains numerous every direction and owing to the porous character of the small nodules of iron pyrites. It may be considered as upper portion of this rock, it affords but a poor building equivalent to the shales of western New York material; while the lower part of the rock is more compact and has marks of regular stratification. This is THUNDER BAY LIMESTONE. more clearly exhibited on Round and Bois Blanc island, and where a much better building material can be This limestone occurs at the south cape of Thunder bay, procured, than any seen on the Island of Mackinac. forming an abrupt cliff, which rises directly from the water to the height of twenty feet. It is composed of Hornstone, striped jasper, imperfect hogtooth spar, alternating layers of compact and shaly limestone, and calcareous and fluor spar, and some very imperfect fissile clay slate; the latter of which forms a considerable fossil remains, are occasionally found imbedded in this portion of the cliff, containing nodules of iron pyrites and rock. The whole exposed portion has the appearance of chert. Most of the rock is of but little value for having been very much shattered by an irregular economical purposes. It contains numerous fossils, upheave. among the most characteristic of which, are the Atrypa aspera, and prisca; Delthyrus speciosa, Calymene bufo, Limestone of a similar character to that above described, Gorgonia, Millepore, Catenipora stellata, Cyathophyllum was examined on the main land, to the west of Mackinac dianthus, Calamapora spongites, Pentremites pyriforrnis. island, forming the high bluff known as the “Sleeping Rabit;” also forming the bed of the lake west of old Fort BLACK LIMESTONE. Mackinac, and extending westerly as far as point Wabachance. This rock is seen cropping out at intervals on the lake coast, from Thunder bay island to Middle island, but it either occurs below the surface of the water or so little ROCKS OF LAKE MICHIGAN. elevated above it, after leaving outer Thunder bay island, Rock has not been found to outcrop in that part of the as to be difficult of examination. state north of Grand river, lying between townships Most of this rock is of an inferior character and furnishes seven and fifteen north, and west of the meridian. But a coarse, rough, building material, and is of very little were the superincumbent sands and clays removed so value in an economical point of view. Some portions of it as to expose the rocks to view, they would be found to are of a sub-slaty character, highly charged with correspond with those passed over in going south-east bituminous, while portions are nearly composed of from the rapids of Grand river to Monroe county, being a congries of fossils. It is undoubtedly the animal matter succession of sandstones and shales. from the fossils that gives to this rock its bituminous Near the Manistee river, in township fifteen north, character. limestone appears in elevated cliffs; which rock is Among the most characteristic fossils found in this rock, probably referable to the same series as that of are the Calymene bufo Rowii and Blumembachii, Atrypa Monguagon, in the south-east part of the state. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 34 of 59 BLUE AND LIGHT GRAY SHALES. five to thirty feet, and for the sake of a more minute description they may be sub-divided, and considered in This shale crops out on Grand Traverse bay, (in a descending series, as follows: township thirty-one north,) forming a cliff of from five to fifteen feet in height, is of a light gray or blue color; most of it highly argillaceous, and is divided into thin laminae, varying in thickness from one-eighth of an inch to two inches. The thin laminated parts of the shale are very friable while the thicker layers are more compact and calcareous. Minute crystals of spar were seen attached to and filling crevices in the most compact part of this shale. I was unable to detect any fossil remains in the shale.

BLACK SHALE. This shale forms a series of abrupt cliffs, of from one to twenty feet in height, for the distance of nearly a mile on Most of the limestones of this bay are of an inferior the coast of Grand Traverse bay (in township thirty-two quality for economical use. They are very much north,) being four or five miles north from the blue shale shattered, presenting in that respect a strong before described, and lies below it. resemblance to the sandstones of the southern part of This shale is slightly bituminous, contains numerous the state. Some portions of the rock on this bay are so nodules and specks of iron pyrites, is very friable, shattered, as to have the appearance of a mass of loose disintegrates rapidly before the action of the waves to blocks. Fossils were found in a very perfect state; which it is exposed, and closely resembles in character, among the most characteristic of which are the Atrypa composition and superposition, the shale of Sulphur prisca, Productus, Strophomena, Calamapora island of Lake Huron, with which it may be regarded as polymorpha, Cyathophyllum vesiculosum, Isotelus gigas, identical in geological position. sarcinata, Ceriopora verrucosa, Catenipora labyrinthica. This shale was also examined in the north bank of Pine BLUE LIMESTONE. lake, (in township thirty-three north, range seven west,) This rock was found outcropping at the first point west of where it is but slightly elevated above the water of the Pine river; also, south of the head of Little Traverse bay, lake; contains like the shales before described, and is there of a light blue color. It is elevated a few feet numerous nodules and specks of iron pyrites, is slighty above the water of the lake and stream, where it bituminous, and is equivalent to the black shales of embraces the black bituminous limestone, next Lakes Huron and Michigan. described. The latter occurs here, in two or three thin Associated with the shale at this point, are large angular layers, which are filled with fossils. masses of fœted limestone and shale connected The blue limestone is very compact, in strata varying in together in the same mass; and these masses are thickness from one to two feet. These strata are much frequently traversed by thin veins of pearl spar; the latter warped, as if by irregular uplift, destroying all regularity also filling the small cavities formed in the rock. The of dip. It contains numerous fossils, analagous to those masses of fœted limestone above described, occupy of Middle island of Lake Huron. places simply in the lower portions of the shale stratum. BLACK LIMESTONE (SUBORDINATE.) CORNIFEROUS LIMESTONE. Embraced in the blue limestones, is found the out The rock to which I have given this name is of a light thinning edge of the black limestone of Thunder bay gray color, regularly stratifyed in layers varying from one- island. It is seen in the bay beneath the waters, and fourth of an inch to twelve inches in thickness, and is between one and two miles south of the head of the bay, very compact; some portions of it affording a good in the bed and banks of a small stream, where it consists building material. It contains large quantities of of several layers, from two to twelve inches in thickness; imbedded hornstone, in layers, from one to twelve is highly bituminous and is almost wholly composed of inches in thickness, and which breaks into small blocks congeries of shells, which undoubtedly give to it its on exposure to the atmosphere. This limestone is bituminous property. It burns when thrown upon the fire, destitute of fossils, in that portion which was examined. with a brisk flame, so long as any of the bitumen LITTLE TRAVERSE BAY LIMESTONES. remains, but the mass is not reduced in size by the burning. These limestones agree in geological position and character, with those of the cliff in Thunder bay, Thunder It is the bituminous character of this rock, which has bay island and Middle island of Lake Huron. given rise to the reports that coal existed in the vicinity of the Little Traverse bay. The limestones of Little Traverse bay rise directly from the water, forming abrupt cliffs, varying in height from Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 35 of 59 The Indians attach great value to this rock, for its Maps of the Counties.—The labor of correcting, while in inflammable quality; and upon inquiry being made of the field, maps of those counties which were assigned to them, respecting it, they professed to be entirely ignorant my geological and topographical supervision, has been of the existence of any rock of that character, in their completed, and the plats are now in the hands of the region of country. state topographer, to be prepared for publication. A great mass of information, both of a practical and purely Deer Licks. scientific character, and which could not be transferred Springs which have their waters slightly saturated with to the maps, nor be suitably embodied in the annual muriate of soda, and the salts of lime and iron, are reports, has been compiled from my field notes, occasionally to be met with, in that part of the state arranged for future reference, and for such use as may under consideration. In character and quality of water, be found advisable in the final report on the survey. they are equivalent to those which are found in Macomb Particular attention has been devoted towards the full and St. Clair counties, and cannot be considered as of collection of all such details as would give a much practical importance. completeness to the several objects aimed at, in this department of the survey, and I may be permitted to say Ancient Lake Ridge. that no source of information, known to me, has been In prosecuting my examinations in the north part of the neglected, which could subserve interests of so southern peninsula, portions of ancient lake ridges were important and comprehensive a character. met with, which were found to correspond with that Purpose of present report.—The report of Mr. Douglass, whose character was determined by Mr. Hubbard, and of last year, embraced a general view of the extent of the described in his report of last year, as occurring in the coal bearing rocks, so far as then ascertained, and their southern part of the state. No large continuous ridge details in the counties of Jackson, Ingham and Eaton; was met with, through the country examined by me, but my own having been confined to the rocks below the rather a series of small ridges, which were found to be lowest of the coal bearing series. Without further composed of water worn pebbles, gravel and sand, not recapitulation of the facts heretofore submitted than may unlike those composing the present lake beach, and be unavoidable, I propose, in the present report, to having an elevation, as nearly as I was enabled to judge, exhibit a comprehensive view of all the rock formations, of one hundred and forty feet above the present water throughout the organized counties of the state. level. The “geological section,” hereto prefixed, will serve to These ridges were found the most fully exhibited on the exhibit, at a glance, the succession of the rock islands and on the main land bordering the straits of formations, from the universally superimposed sands Mackinac, and occur under circumstances that would and gravels, down to the great limerock formation of the seem to show that the water of the lakes had subsided southern portion of our state, bordering on Lake Erie. It gradually, or, (which would produce the same effect,) the is intended to show the rocky basis which would be land had been gradually elevated. exhibited to view, if the country could be cleft through, in COLUMBUS C. DOUGLASS, a line from Lake Erie to Maple river, in Clinton county. Assistant Geologist The rocks in this section are grouped according to their distinguishing characters and relative position, and each group is distinguished by an alphabetical letter. The sub-divisions of some of the groups, are given in the body of the report. Report of B. Hubbard, Assistant Geologist Detroit, January 24, 1841.

To DOUGLASS HOUGHTON, State Geologist:

DEAR SIR—Immediately upon my return from the portion of our state bordering on Lake Superior, where my services as assistant had been required during a large part of the season, I recommenced the detailed surveys in the organized counties of Michigan proper. These were conducted with a more especial view to the determination of the extent and value of the coal district of the peninsula. The counties in which minute examination have been made during the past season, are Barry, Clinton. Shiawassee, Genesee, Lapeer, St. Clair and Macomb; and examinations have been extended generally over other counties previously examined, in part, in order to the more full and satisfactory completion of the duties assigned me.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 36 of 59 General Geology of the absolutely barren, the variety and due intermixture of ORGANIZED COUNTIES OF MICHIGAN. their components, and more particularly the large proportion of carbonate of lime which is combined with In the “section” alluded to, the rocks, embraced within them, either in the form of pebbles, or in a very the district under consideration, are divided into groups, comminuted state, imparts to them unusual strength and as follows: fertility. The latter circumstance is that which so admirably adapts them to the growth of wheat, and in A. Erratic block group, or Diluviums.—a. Alluvions, this respect, most of the soils of the peninsula may fairly ancient, recent. be pronounced unrivalled. B. Tertiary clays. Upper coal and shales. Whatever may have been the causes which swept these Lower coal and shale. materials over the face of the rocks, whether oceanic C. Coal measures. Included sandstones. currents or bodies of floating ice, the character of these Limestone stratum. diluviums, as well as numerous accompanying facts, D. Sub-carboniferous sandstones. plainly imply that they came in a direction northerly from E. Clay and kidney-ironstone formation. their present beds, and often from great distances. F. Sandstones, of Point aux Barqes. Consequently we find intermingled, as well as scattered G. Argillaceous slates and flags, of Lake Huron. upon the surface, numerous rounded fragments of those H. Soft, light colored, sandstones. primary rocks which are known to exist in the peninsula I. Black, aluminous slate. of northern Michigan and in Canada, from the size of the K. Limerocks, of Lake Erie. largest “hard-heads” down to fine gravel. In proceeding from our state southerly, these deposits are found These will now be considered, as nearly as may be, in gradually to thin out, evincing a diminution of the their consecutive order, beginning with the highest in the sustaining power with the increased distance from the series. original bed of the transported materials. So that, while ERRATIC BLOCK GROUP, OR DILUVIAL DEPOSITS. the peninsula of Michigan has been most liberally supplied with an uncommonly deep and arable soil, These consist of sand, pebbles, and large water-worn made up of a variety of materials, the states of Ohio and masses of previously existing rocks, with occasional Indiana, on the south, are in great part destitute; its small, local beds of clay. They have a thickness varying place being supplied by the clays of the next lower from one to upwards of one hundred feet; they form a formation. universal mantle to the rocks, and constitute the soils of all the interior counties. The deposition of these materials took place with or without apparent order and uniformity, according to the As this whole deposit is one of transport by water, and is character of the existing surface, and other made up of the detritus and disruptured fragments of circumstances which may have governed the heterogeneous formations, its character depends upon transporting forces. From this cause considerable that of the rocks from which it is derived. For instance, variations are to be found in the depth, nature, and sand constitutes by far the greater proportion, and this composition of the diluviums, and hence, also, material circumstance may be, in part, accounted for, from the differences are occasioned in the soils and other fact of the immense extent of sandstone rocks existing characteristics of the country. In many places a uniform farther to the north; and in part, by the fact, further stratification has taken place, as if the result of quiet disclosed by the geological researches in the peninsula, deposition. This is more particularly apparent on the that an immense thickness of rocks, mostly sandstone, east and south side of the main ridge of the peninsula, which composed the upper series of the coal measures, and may be considered as a natural consequence of so has been broken up and removed from our geological considerable an obstacle as this partial barrier must series. Fine gravel constitutes the diluvium in the next have interposed to the force of northerly currents. Here, proportion, and is the result of a similar abrasion of rocks wells have been carried to the depth of 90 feet, through of harder materials. Owing to the friable nature of the beds of stratified gravel. sandstones, as might be expected, few large boulders of that material occur. Limestone pebbles and boulders Throughout all the diluviums, thin local beds of clay are are abundant; a condition which also might be looked of frequent occurrence, and occasional strata of hard for, when we take into view the immense extent and pan or cemented pebbles. These clays, unlike those of thickness of the limerocks of our state, they being by far the tertiary, contain little or no lime. the most prominent formation above the primary. Most of the country thus covered by the diluvial deposits, These relations of the component parts of our diluviums, exhibits the action of strong currents and eddies in a give a character to the soils of the peninsula, which very striking manner. Districts of many miles extent enables us to compare them most favorably with those frequently present a continued and close succession of of most other states of the union. Though being very rolling knobs or cones of gravel, with deep intervening generally what may be denominated sandy or gravelly, basins. The more ordinary character of surface is a and often answering in appearance to a description of gentle roll or slight undulation occasionally subsiding to a soils which, in the eastern states, are considered as perfect plain. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 37 of 59 Except where a deposit of clay underlies, the growth of Their successful drainage is no longer a matter of timber is almost invariably scanty, constituting what are experiment. Scarcely a marsh of much extent exists, denominated “oak openings.” The character of their which is not capable of thorough drainage, with timber changes with the varying conditions of the soil, comparatively small expense, and, when thus subdued, from white and black oak to burr oak or hickory, and the of furnishing a soil rich almost beyond comparison. The plains are frequently altogether destitute of timber. A literally exhaustless beds of marl and peat, with which dense growth of the usual hard wood timber sometimes these marshes abound, constitute another item of value occurs over isolated tracts, in swales, or along banks of no less important. But the consideration of these may streams. Of the character of country described are more properly be referred to the head of recent found the three most southerly ranges of counties, with alluvions. the exception of those which immediately border the But though affording a medium for the absorption of rain peninsula, on the great lakes, together with parts of the waters and their percolation through strata of gravel or adjoining counties, and the counties of Ingham and quicksand, the diluviums are rendered sufficiently Eaton. All the latter have a sub-stratum of clay, retentive, by the alumine contained in them, and by belonging to the great deposit to be presently described, seams of cemented gravel and sand. Were it not for and in consequence differ very materially in surface, soil this, the moisture absorbed by our light, sandy soils, and timber. would soon be drained off and lost to the crops. A sub- To this extreme thickness and comparatively loose stratum of cemented gravel, retentive of water, is texture of the diluviums, may be ascribed the great common to many if not all the prairies, and to this abundance of springs, and consequently of the small circumstance may no doubt, in great measure, be streams which irrigate the whole surface of the state, ascribed their accumulation of rich loam and consequent affording abundance of that element so desirable to the fertility. farmer. An undulating surface gives to most of these a Much curious inquiry has been excited on the question sufficiently rapid flow to preserve a healthy current and of the causes which produced the peculiar varied and to furnish a sufficiency of mill power. From the same open character of so large a portion of our peninsula. cause, also, little difficulty is experienced in obtaining After the view which we have just taken of our diluviums, pure water by sinking of wells, and it may safely be said it may seem less a matter of surprise, that portions of the that Michigan is better supplied with living water, state should be adapted to the production of a dense uniformly distributed, than any other state in the Union. growth of hard timber, and others only to the several The vast number of small lakes for which Michigan is so species of oaks or to hickory, according to the remarkable, are due to the same causes. They occupy continually varying conditions of the soil and its sub- generally deep hollows, seemingly scooped out of the strata. The existing analogies of the vegetable world, mass of diluvium, and are fed by the living springs that which exhibit similar results elsewhere, might lead us to percolate through it. The number of these peninsular infer these changes, and we may, without doubt, lakes is stated by the state topographer at not less than attribute to the peculiar characteristics of our diluvial 3,000; being in proportion of one acre of water to every envelop, and its varying conditions, the accompanying thirty-nine of dry land. peculiarities in the features of the country and the growth and character of its timber. Another striking feature in the peninsula landscape, is the number and extent of wet prairies or marsh. Of How far the impervious character of the “hard pan,” these the proportion is much larger than of the lakes, which so generally, if not universally, forms the sub- and they often cover many miles of surface. These have stratum to the prairies and plains, may account for the their origin also from springs, issuing from the diluvium, destitution or sparse growth of large trees, we are not aided often by the artificial dams of the beaver, and from altogether prepared to decide, and, therefore, avoid for being originally mere pools or shallow lakes, in time they the present, considerations which at best may be become receptacles for beds of marl and peat. From the considered somewhat theoretical. Nor will we assume to very tolerable hay which these prairies afford, and the decide, with confidence, upon the extent of the effects very early supply of tender “feeding” for cattle, in the produced by the ravages of the annual fires which spring, these apparently waste places have been an formerly swept over these tracts. It is but reasonable to invaluable aid to the settlement of the country. The conclude that all these, and perhaps other concomitant primitive settler came hither, not to a desert waste or a causes, have operated together in producing the results “howling wilderness,” but to lands cleared without aid we witness, while, according to peculiar circumstances, from the woodman’s axe, and verdant with unsown one of these several causes may have operated more or crops. He did not wait to provide pasture, but brought less powerfully than others. his herds and flocks with him, and the marshes furnished ANCIENT ALLUVION. them ample sustenance throughout the year. And we hazard nothing in saying that these marshes, waste as As the consideration of that immense mass of materials many of them are now suffered to be, are destined to to which has been applied the name of diluviums or become still more valuable in sustaining the failing vigor erratic block group, was necessary, in order to a correct of the country whose youthful prosperity they promoted. appreciation of those lesser deposits, now to be

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 38 of 59 considered, (which are associated with, and in fact RECENT ALLUVIONS. compose a part of the former,) that important group Under this head I shall here allude only to local beds of claimed our first attention. We come now to the marl, bog ores, and peat. consideration of a class of deposits which may be called alluvial. Marl occurs in the greatest abundance, universally distributed throughout the diluvial district, and consists of Some interesting facts in relation to the assumption, that local deposits, which originate solely from the lime so the waters of the great lakes were formerly at a much profusely contained in the diluviums. Such beds are in higher level than at present, covering a large part of the constant process of formation and increase, wherever border portions of the peninsula, were noticed in my that ingredient exists. As it is present in a much less report of last year. During the past season, a degree in the ancient alluvion, no extensive beds are continuation of the “ridge,” which is supposed to coincide consequently found throughout the district occupied by with the beach of the ancient lake, has been traced the latter. through Macomb into St. Clair county; and further facts, confirmatory of the positions assumed last year, were Bog iron ores are deposits, originating in a similar observed in other more northerly districts. In the county manner, from the iron contained in the soil, which is of Macomb, this ridge has been much broken up by dissolved out by the rain waters and collects in low crossing streams, and is very irregular, showing grounds. frequently the existence of large entering bays and Peat beds are exclusively of vegetable origin, and are curvatures of the coast. This was the more particularly common both to the alluvial and diluvial districts. noticed, from the fact that elsewhere, so far as observed, the course of the ridge is very remarkably continuous The character, abundance, and value of the marl, peat, and well defined. In this county, also, a number of and bog ore beds of our state having been fully dwelt inferior ridges of evidently similar origin, were observed, upon in the reports of last year, I shall make no further between the main one and the present lake shore; remarks upon their practical applications. I cannot leading to the supposition, that the subsidence of the avoid, nevertheless, once again directing the attention of waters did not take place gradually and constantly, but the farmer of Michigan to the fact of the unexampled that sudden lapses occurred, and the water line had abundance in which the two former occur, conveniently been stationary at intervals. distributed for universal use as a manure, and urging the The soil and detrital matter superficially covering that use of them, as the cheapest, and, in most cases, the portion of the peninsula which is embraced between this best of mineral manures, and which will be found a very important means of improvement in his agricultural ancient lake ridge and the present shores of the lakes, I have denominated ancient alluvion, to distinguish them, economy. as well from alluvions now in process of formation, as Organic Remains. from the immense mass of diluviums which overspreads the whole interior of the state, beyond this separating Bones of the Mastodon were last year discovered, in the ridge. ancient alluvion, in the western part of Macomb county. They were mostly so much decayed as not to bear The portion thus distinguished by alluvial deposits, exposure to the atmosphere, and a molar tooth only has embraces a broad belt of border country, varying in been preserved. Similar relics were, several years ago, width from about 25 to 50 miles. It is, with small local disinterred on the Paw Paw river in Berrien county. exceptions, heavily timbered and very level. But, on passing the bounding ridge, there is, in general, an There is now in possession of a gentleman in this city a almost immediate change to a soil of coarser character, vertebral bone of enormous size, said to have been and a more undulating surface. This ancient alluvion is found, many years ago, upon the St. Joseph river, and a deposit, from a quiescent condition of the waters, and which is pronounced by the state zoologist, Dr. Sager, to similar to that which is now taking place in the beds of be the caudal vertebra of a whale. It measures in the present lakes. It forms, in general, but a thin mantle vertical diameter, including spinous process, 18 inches; to the underlying formations, consisting often of mere transverse diameter, including lateral processes, 2 feet; ridges of sand, and, owing to the deprivation of its lime, diameter of body, 11 inches; length of body, 10½ inches; has, in general, less fertility than the diluviums. length of spinous process, 9 inches. Its weight is 21 lbs, which is probably less than one half its original weight, The heavily timbered district is not altogether coincident as the bone is partially decayed. with the extent of this alluvion, but is dependent chiefly upon the following cause. Throughout their whole TERTIARY CLAYS. extent, the alluvions are underlaid by the tertiary clays. These extensive deposits belong to an era subsequent These are a formation anterior to both the diluviums and to the removal of the upper coal bearing rocks. They alluvions, and are frequently found extending far beyond cover all the border counties on the east and west the old lake ridge. The country thus underlaid, is that slopes of the peninsula, and, in some instances, stretch which is almost wholly clothed with a dense growth of far inland. These clays extend over more than two-thirds timber. This formation will be found described under the of that part of the state which lies south of Saginaw, head of tertiary clays. Maple, and Grand rivers, embracing nearly the whole of Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 39 of 59 the counties of Ottawa, Allegan, Van Buren, Berrien, Limestone Stratum. Monroe, Wayne, Macomb, St. Clair, Sanilac, Huron, Tuscola, Saginaw, Lapeer, Clinton, and Eaton, and a As this stratum, from its position, (being the lowest in the large portion of Ingham, Genesee, Shiawassee, Ionia, series,) determines the extent of the rocks considered as Kent, St. Joseph, Branch, Hillsdale, and Lenawee. The composing our coal basin, I shall, for the sake of greater remaining portions of the counties last named, and very precision, give to it the first consideration. nearly the whole of Oakland, Livingston, Washtenaw, A gray limestone, in irregular, detached beds, is found Jackson, Calhoun, Kalamazoo, and Cass, are destitute along the extreme border of the coal bearing of this sub-clay formation, and their diluviums rest sandstones. They are evidently relics, in place, of a thin immediately upon the rocks. but extensive stratum, and as no coal has been found A dense growth of timber almost invariably accompanies below this rock, I have assumed it as the terminating this formation, whatever may be the immediate soil. We rock of the “coal measures” proper of our state. find this observation applicable to large portions of Following this rock, as it makes its occasional Eaton, Ingham, Clinton, Shiawassee, and Genesee appearance, the southerly limits of the coal basin may counties, though these counties are based in part on the be traced by a line, drawn from the Shiawassee river, at sandstone rocks of the coal series, and have sandy, Corunna, through the easterly parts of Ingham and diluvial soils; while the sandstone country south of them, Jackson, between ranges one and two east, to near presents little else than oak openings and plains. Napoleon, in the latter county. It then turns westerly through town three -south, ranges one and two west; These clays are an extension of the same formation from whence, taking a direction north-westerly, it which covers the western and northern part of Ohio, and pursues an irregular line, passing through Bellevue in the east and north of Indiana, and which constitutes the the south-west corner of Eaton county, to Grand Rapids, soil of a large proportion of those districts. in Kent county. Here the limerock is more extended, and The upper portion is a gravelly, yellowish clay, varying in a thickness has been determined to it of fourteen feet. thickness from one to fifteen feet, and having an average The rock is characterized by the fossils Nucula and probably not exceeding 5 feet. Beneath this is a similar Cyathophyllum vermiculare. This stratum affords the clay, of a blue color, and which in some places has been only limestone for the kiln, or other purposes, except found to exceed in thickness one hundred and twenty occasional boulders, to be found in the interior of the feet. Both clays contain at least 20 per cent, by weight, state, and its value is the more to be appreciated as the of carbonate of lime, and this marly character injures formation is itself of very limited extent. them materially for the manufacture of bricks or pottery. Lower Coal. On the western slope of the peninsula, the place of the But two continuous beds of workable coal are yellow and blue clays is sometimes supplied by clay of a ascertained to exist in the state. The lowest of these, reddish color, of great thickness. No fossils have yet lies at a small distance only above the limestone been discovered in any of the clays of this formation. stratum, and is associated with a very thick bed of shale, which is also sufficiently bituminous to answer the COAL MEASURES. purpose of an inferior coal. The rocks which include the coal beds of our state, Coal of Jackson County.—That portion of the lower coal occupy, comparatively, but a small portion of that part of bed which underlies a portion of this county, makes an the state under consideration, and are embraced within outcrop in the valley of Sandstone creek, town of Spring the counties of Jackson, Calhoun, Ingham, Eaton, Kent, Arbor, and has there been penetrated to the depth of Ionia, Clinton, Shiawassee and Genesee. They consist three feet. The thick bed of shale opened at Jackson of strata of sandstone, shale, coal and limestone. undoubtedly is associated with and belongs to this coal Covered as these rocks are, with thick deposits of stratum. diluviums and clays, they make out crops at but few Coal of Ingham County.—Passing down the easterly points, and the determination of their order and extent side of the basin, the coal is again met with, in the north- has been a matter of no small difficulty. From the dip of east corner town of Ingham county, where it is embraced the rocks composing these measures, there can be little in a succession of shales and friable sandstone, doubt that the coal basin extends northerly beyond the cropping out in the banks and bed of the Red Cedar counties named, perhaps as far as to the head branches river. The coal has here been penetrated two and a half of the Tittabawassee and Maskego rivers. But that feet. But neither here nor in Jackson county is the entire country is as yet almost wholly unsettled, and though thickness of the bed determined. “The coal at this point,” partial explorations have been made through it, since the as is observed in the report of Mr. Douglass, of last year, commencement of the geological surveys, the thick “is very accessible, and must, ere long, prove of great mass of overlying materials has hitherto prevented a importance. It is situated on a stream that may be made determination of the northerly extent of these rocks. navigable for flat bottomed boats and perogues, with comparatively small expense, for a considerable portion

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 40 of 59 of the year, and opening a direct communication with Most of this coal is inferior in quality and thickness to the Lake Michigan.” lower coal. It composes several layers, not exceeding in thickness from one to two feet each, and is embraced in It may here be observed that the coal of this lower bed, alternating strata of dark gray shales, blue clay, universally, has more than usual compactness and sandstones and thin beds of argillaceous iron ore, purity, and is equal to the best bituminous coal of exceeding in the whole twenty feet. Pennsylvania. Coal of Eaton County.—Sections of the alternating strata Coal of Shiawassee County.—The coal again makes its of coal and accompanying rocks, taken on Coal and appearance, at the border of the basin, near the county Grindstone creeks, were given by Mr. Douglass in his seat of Shiawassee county, where it crops out between report of last year. As that report contained full local thick and extensive layers of sandstone, in the banks of details of all the coal-bearing rocks of Jackson, Ingham the small creek entering Shiawassee river. The coal has and Eaton counties, I shall here allude to the rocks of here a thickness of from three and a half to four feet, and that portion of the state only in such a general manner is accompanied by shale, the entire thickness of which is as will be necessary, in order to afford a comprehensive not ascertained. This coal is very eligibly situated for view of the extent and value of the coal measures of our mining. It is of excellent quality, and the dip is so slight state. By reference to the document alluded to, it will be that but little depth of excavation will be required. This is seen that, though inferior in thickness to the lower coal the only locality in the state where coal, to much extent, bed, the several strata of coal exposed on the creeks has been raised for economical use. Both the coal and above mentioned, have an aggregate thickness of from associated shale are constantly employed to great two to three feet, and will, no doubt, prove of importance advantage at the steam mill of Mr. McArthur, in Corunna, under a more settled condition of that portion of the as well as by neighboring smiths. state. From an area of eight by nine feet Mr. McA. raised four INCLUDED SANDSTONES OF THE COAL MEASURES. hundred and sixty bushels of coal and shale, and he informs me it can be sold at the county seat for ten cents Gray and yellow Sandstones.—The sandrocks included per bushel. between the upper and lower coal are mostly of a coarse, quartzose character, and of a light gray or yellow The underlying limerock stratum makes an outcrop color. Most of the strata are friable, but harden on about a mile south-west from this point, in a bed of exposure. They are distinguished from the quartzose probably many acres in extent. sandstone below the lower coal, by containing Shales of Flint river.—The coal bed and its impressions of the coal plants. These are referable accompanying shale may be traced still further east, to chiefly to the genera Lepidodendron, Stigmaria and the Flint river, in Genesee county. Here the former Calamites. probably has nearly thinned out, as only loose masses These rocks are found outcropping at numerous points are found, in the bed of the river. The associated black through the northern part of Jackson county, the western shale and slate may be observed in the river banks, part of Ingham and eastern part of Eaton counties, and (town eight north, five west,) where it attains a thickness portions of Calhoun, Clinton, Shiawassee and Genesee. of sixteen feet, and is underlaid by the sandrock. In all of the above named counties they occur in The coal of the Shiawassee and Flint rivers, appears to situations which admit of being economically quarried, occupy the extreme edge of the coal basin, which here and may often be obtained in firm blocks of any thins out into a wedge form, narrowing gradually until it dimensions required. From this series of sand-rocks terminates in a mere point, probably as far easterly as was furnished the material for the construction of the Lapeer county. The inclination of the strata is north- state penitentiary at Jackson, and at several places, as westerly, to an amount which would soon carry the coal at Napoleon, excellent grindstones are manufactured beneath the surface; but appearances seem to warrant from it. the conclusion, that at this point a large part of the rocks Red or variegated Sandstone.—This rock immediately of the coal measures, continued northerly, have been underlies the upper coal and shales. Its outcropping entirely removed. edge is found in the valley of Grand river in the northern Upper Coal part of Eaton county, and in the banks of the Lookingglass river, in the adjoining towns of Clinton The outcrops of this coal, within that part of the state county, and in township seven north, six west, Ionia under consideration are of small extent. It is found at the county. No fossil plants were discovered in this rock. It surface on and near Grand river, in the northern part of has been employed with advantage as a building Eaton county, and with its associated shales and material. The entire thickness of the included sandstones, occupies the central part of the coal basin, sandstones must be several hundred feet. probably including the whole of Clinton and Gratiot counties. Except in the extreme south-west corner of The following general section will exhibit, at one view, the former county, it lies too deep for examination. the relative order and thickness of all the rocks of our coal measures, above described, so far as a sub-division of them has been found practicable. Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 41 of 59 they are reached in almost all the deep wells. It is probable, also, that these rocks occupy most of the eastern portions of Jackson and Shiawassee counties, east of the limestone stratum above described; and they make their appearance, at its eastern edge, on Lake Huron, near the entrance of Saginaw bay. The aggregate thickness of these sandstones may be estimated at upwards of 300 feet.

CLAY, CONTAINING KIDNEY ORE OF IRON. This very valuable formation immediately succeeds to the sandstones above described, underlying them and cropping out at the extreme southerly bend of the basin. It occupies a part of the south-western portion of Calhoun county, the whole north-eastern portion of Branch county, or nearly so, and part of the western and central portions of Hillsdale. It consists of an indurated, grayish brown clay, having much the appearance of a shaly limestone or dark gypsum, regularly stratified, in which are imbedded nodular masses of kidney ironstone. This is a rich and valuable ore and occurs at several points conveniently for working. This formation is the lowest that is discoverable in this portion of the state, and is not certainly known to make an outcrop elsewhere. For further description of this clay and its contained ore, I refer you to the annual report of the State Geologist of 1840, and to my own appended thereto, for many practical considerations relative to the value of the ore The rocks in the above section embrace all those which and its imbedding clay. This formation is marked F, in are included in the division marked C, in the geological the plate. section, prefixed to this report. SANDSTONES OF POINT AUX BARQUES. *Counties of Clinton and Eaton. These are mostly a coarse, greenish gray or rusty yellow SANDSTONES IMMEDIATELY BELOW THE COAL. rock, in some of the layers approaching a conglomerate. They form cliffs along the shore of Lake Huron in Huron These sandstones, (marked D, in the plate,) as well as county, rising at Point aux Barques to twenty feet. most of the formations below the coal, were fully Fossils are rare, but Atrypa and Calymene were described in my report of last year. I shall, therefore, now obtained. These sandstones occupy the coast north of notice them only so far as to exhibit their relative position town seventeen, being visible in ledges for about twenty in the series, viewed as a whole, and the extent of miles. The upper portion of the series contains country occupied by them. numerous, small imbedded pebbles of quartz, so as to These sandstones, which, in the report alluded to, are resemble a conglomerate or puddingstone, but no great described under the name of fossiliferous, ferruginous thickness is observable of rock possessing this sandstones, excepting in some of the uppermost strata, character. are generally fine grained and of a yellow color. Some An extension of the outcropping edge of these strata of the latter abound in marine fossil shells, among sandstones, it is probable, gives rise to that swell of land which the genus Nucula is very abundant, and there which forms the summit level of the peninsula, stretching were observed species of Atrypa, Bellerophon, in a south-westerly direction from Point aux Barques to Euomphalis, and Pterinea. Hillsdale county, where the green and yellow Though here classed as beneath the coal rocks, these fossiliferous sandstones, above described, overlie it. But sandstones are associated with that series of rocks throughout this whole extent no outcrop of the rock is which are usually regarded as belonging to the visible, owing to the thickness of the diluviums. carboniferous era. They occupy nearly the whole of These sandrocks, taken in connection with the formation Calhoun county, the lower half of Jackson, and the next described, bold a place in the geological series, northern half of Hillsdale county; through which counties corresponding to the “waverly sandstones,” and their outcrops may be observed at numerous points, or “conglomerate,” of Ohio, but the deposition seems to Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 42 of 59 have been made under somewhat differing refer you. This slate contains much sulphuret of iron; it circumstances. No well defined series is apparent in our will burn readily, and in general character and position, it state answering fully to the Ohio conglomerate; though agrees with the black shale stratum of Ohio and Indiana, the upper portion of the sandstones of Point aux but its thickness is probably not nearly so great. Barques approach that character. LIMESTONES OF LAKE ERIE. The whole thickness of these sandstones probably This formation, which immediately underlies the black exceeds 250 feet. This group is marked F, in the plate. slate, is by far the most continuous and extensive rock CLAY SLATES AND FLAGS OF LAKE HURON. formation in the western states. It is found outcropping in several district ranges throughout Monroe county, Alternating with the lower portions of the sandstones of forms a considerable part of the lake coast and serves Pt. aux Barques, are strata of slaty sandstone, as a basis to the islands at the mouth of Detroit river, approaching the character of slate; to which succeeds a and is an extension of the rock formation which occupies compact, micaceous clay slate of a blue color. This the whole western part of Ohio and the northern and latter rock continues to occupy the coast for about thirty eastern portions of Indiana. It is found forming the bed miles, or from township twelve to township eighteen of Lake Michigan at its head, and undoubtedly is the north, and rises in ledges of from five to fifteen feet. underlying rock of a considerable portion of the extreme The slaty sandstones intervening between these clay southwestern part of our state. The overlying tertiary slates and the overlying coarser sandstones are of a clays conceal a great part of this formation. flaggy structure in some of the layers, and from these The character and economical adaptation of these were obtained those fine flagging stones which have limestones have been sufficiently set forth in former been extensively used, for three years past, for reports, to which, accordingly, I refer you for detailed pavements in the city of Detroit. Some of these strata information. are distinguished by ripple marks. No fossils have been discovered in this formation. Among the fossils contained in the limerock I distinguish the following genera; Calymene and Asaphus, These slates and alternating sandstones may be Cyathophyllum, Productus, Terebratula, Spirifer and considered as the upper salt rock of our state. They Dethlyrus, Bellerophon, Atrypa, Strophomena, have been passed through in boring for salt at Grand Orthocera, Encrinus, Retepora and Madrepora. Rapids, and found to yield strong supplies of brine. At this point they are found also to alternate with beds of In proceeding southerly from the outcrops of the slates gypsum and gyperous marls, as will appear by reference of Lake Huron, a limerock is met with, which may be to the table of the strata passed through, given on a seen in the bed of a small stream near the lake coast, subsequent page. The thickness ascertained to these town nine north, sixteen east. In character and fossil slates, at that point, is about 170 feet. contents it bears a resemblance to that of Monguagon, Monroe county; but its position would seem to indicate it SOFT, COARSE GRAINED SANDSTONE. rather as an included stratum in the series of sandrocks A series of sandrocks answering to this description, and and shale, which are higher in the geological series. generally of a dark color, succeeds to the clay slates and The following general section will exhibit the order of shales last above described, and has been penetrated at succession and approximate thickness of the rocks, the borings at Grand Rapids, 230 feet. There are, as above described, lying below the coal basin, and is a yet, no data for ascertaining the entire thickness of this continuation, of the table given on page 130 of the series, since it does not make its appearance at any successive rock formations of the settled portions of our point on the coast of the peninsula, this rock evidently peninsula: forming the bed of Lake Huron, near its foot, and lying too deep for observation. In relative position and perhaps in character, this rock, or a portion of the series, corresponds with the lower salt rock of Ohio and Virginia, and is the rock from which, in these states, the strongest supplies of brine are obtained. The result of the borings in our own state, thus far, would seem to confirm the opinion that this rock is the equivalent of the lower salt rocks of those states.

BLACK, BITUMINOUS, ALUMINOUS SLATE. Underlying the sandstones above noticed, though, also, nowhere observed to make an outcrop within the portion of the slate now under consideration, there is a well characterized black, bituminous slate. This rock makes an outcrop much farther to the north, and is described by Mr. Douglass, in his accompanying report, to which I

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 43 of 59 to, is, at present, in an uninhabited condition; the surface, moreover, is very generally level, and so completely overspread by the deposits of diluviums and tertiary clays, as totally to conceal the rock formations. Surveys have, however, been extended into that region, so far as was practicable with the means afforded, and much valuable information is collected. If I am correct in the above conclusion, the coal bearing sandstones, or, strictly speaking, the coal basin, occupy an extent of surface, nearly oval in form, whose centre very nearly corresponds with the true centre of the peninsula. The tract thus embraced is 150 miles in length, north and south, and upwards of 100 in extreme breadth; covering an area of about 11,000 square miles, or one-fourth the entire area of the lower peninsula. It may be added, that the average dip of all the rocks described, does not probably exceed 15 feet in the mile; though the dip may be said to vary, at different points, from 10 to 20 feet per mile. Borings at the salt well, Grand Rapids. The borings for salt at the village of Grand Rapids, Kent county, commenced in the limerock stratum, mentioned above, page 125, as constituting the terminating rock of the coal basin. At this point, several of the next succeeding series of sand-rocks appear to have thinned out, and their place is here occupied by alternating strata of clay slates and sandstones with gypseous marls and beds of gypsum. These continued to a depth of 190 feet, and below this the borings have been carried mostly through series of sandrocks, to the depth of 415 feet.

Two beds of beautiful crystalized gypsum were passed The rocks in the above section embrace all those which through, at a depth of about 60 feet, and were found to are included in the divisions marked D, E, F, G, H, I, and be from 4 to 6 feet in thickness. This gypsum, it will be K, in the GEOLOGICAL SECTION prefixed to this report. recollected, from the notice of it in former reports, Dip of the Rocks. appears at the surface at Gypsum creek, three miles distant; showing an inclination to the rocks, at this point, Great irregularities of dip are observable in all of our of about 20 feet in the mile. rocks, which circumstance has increased the difficulty of determining the precise relative position, extent, and By reference to a map of the state, it will be apparent thickness of the several strata. Many of the sandstones that the strongest brine springs, (among which are belonging to, and immediately underlying the coal, are included those in the vicinity of these borings,) make much shattered, as if by a quick vibratory motion, and a their appearance along a line which will be found to similar cause has occasioned contortions of dip, in most correspond with the “synclinal axis,” or axis of the dip of of the still, older rocks. I have, therefore, refrained from the rocks composing the great peninsula basin; a noting the amount and direction of dip at the various circumstance which would be looked for, from the fact localities mentioned. All the rocks on the eastern slope that the ordinary law of gravitation would conduct the of the peninsula, south of Saginaw bay, have a general strong brines to the lowest levels of the rock strata. dip north-westerly, while the dip along the southerly and While, therefore, the depth to which the boring must be westerly border of the basin of coal bearing rocks, is carried, in order to reach the lower salt bearing strata, such as to indicate the counties of Clinton and Gratiot as will be greater than would be the case in some other occupying nearly the central part of the coal basin. This portions of the state, the comparative strength of the being the case, the carboniferous sandstones, with their brine obtained may be expected to be proportionably included coal beds, may be considered as extending far increased. to the north of the Saginaw and Grand rivers, possibly as Through the politeness of the Hon. Lucius Lyon, I am far as town 23 north, or to the head waters of the enabled to subjoin a section of the strata passed through Maskego and Tittabawassee rivers. This supposition, at the boring above mentioned. the character of that region, as well as the dip of the rocks, would seem to warrant. But the country alluded Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 44 of 59 which are manufactured, annually, from one to two millions of bushels of salt. Next to those of the state of New York, the Kenawha salt wells are considered the best in the Union. In addition to the quality of the brine obtained, the advantages for the manufacture of salt at the point under consideration, are not exceeded at those places in our country where the manufacture is conducted to the largest extent. The supply of wood for fuel and other necessary purposes is abundant, and will tend greatly to reduce the price for which the manufacturers will be enabled to furnish this article. And, though the whole matter may be said to be still in an incipient state, there is every reason to feel satisfied with the prospect, which so fair a beginning holds out to the state, for obtaining a result so very desirable, as that of supplying her citizens with this important article from the product of her own manufacture.

SUMMARY, Comprising general observations on the economical results of the survey.

From the view we have now taken of the rock strata Below the strata last noted in the above table, the which compose the lower half of the southern peninsula borings have continued through a further depth of 150 of Michigan, it will be seen, that the geology is of an feet, but the data received are not sufficiently minute to exceedingly simple character, while it is, at the same enable me to extend the table. From the information time, richest in the mineral wealth most important to an obtained, they would seem to have passed through agricultural community. mostly soft, light colored sandrocks, of a coarse grain and with a sharp grit, and in the lower portions Michigan occupies a portion of the great valley of the containing cavities into which the drill sometimes falls Mississippi—the richest in the world—and which is several inches. Particles of salt were brought up, and wholly occupied by a broad extent of the rocks classed the rock yields a very strong brine. by geologists in the transition and secondary formations. Of these, the great limestone formation, (of which that of All the strata, from the depth of 81 to 179 feet, or until the west end of lake Erie is a portion, and which the sandrock was reached, were strongly impregnated concluded our view of the several geological groups with saline particles, and yielded brine one-fifth which make up the organized portion of the state,) saturated. These clay slates and marls may be occupies the lowest place, and is the lowest and oldest regarded, as the “upper salt rock,” and they are thus of the rocks found on the lower peninsula of Michigan. shown to furnish a brine superior in strength to that of The upper peninsula of our state, as will be seen by the many of the salt wells of Ohio, and winch, even could no report of the State Geologist, is constituted of lower and stronger brine be obtained, is capable of sustaining a still older rocks, and presents, in consequence, a very profitable manufacture. different aspect, as well as a different mineral character, The brine now obtained, at a depth below the above of from the lower peninsula. about 230 feet, may be supposed to proceed, by veins, The most important of the minerals usually associated from the “lower salt rock,” lying at still greater depth, and with the rocks of those formations which compose lower, from which the strongest and best supplies of brine in or Michigan proper, are iron and lead ores, coal, salt, our state may be expected to be obtained. gypsum, and marls. There are no indications which The immense quantity of fresh or slightly brackish water would warrant the supposition that lead, in any valuable which is discharged through the orifice, (equal to a quantity, exists on the lower peninsula. At least, it may hogshead per minute,) in the present state of the be positively assumed that no ores of lead will be found operations, renders it impossible to decide, with absolute throughout any of the present organized counties of the certainty, what will be the full strength, as well as supply, state. All the other minerals mentioned exist, and some of the strong brine; but, from that which can be obtained, of them, as has been shown, in great abundance. The it is estimated, that of the brine which the well is now results of the examinations into the economical geology capable of furnishing, from fifty to sixty gallons only will of the state, as regards the most important of its be required to produce a bushel of salt. This, it will be minerals, I shall here briefly recapitulate. seen, is equal in point of strength, to that obtained from IRON.—An ore of this mineral, under the form of kidney the salt wells on the Kenawha river of the Ohio, where iron-stone, exists, chiefly in the counties of Branch and the borings are carried to about, the same depth, and at Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 45 of 59 Hillsdale. It is sufficiently extensive to be of much value, now in progress shall have been brought into successful and will give an average yield of about 30 per cent of operation, supposing no stronger brine to be obtained metal. This ore is embraced in the clay formation, than that above stated, the article of salt can be described on page 131 of this report, and a more furnished at a much less price than it now costs the extended notice will be found in the geological report of consumer. 1840, pages 25 and 86. GYPSUM. An extensive deposit of this very valuable Iron, under, the form of bog ores, is found in various mineral occurs in the vicinity of Grand Rapids. The bed parts of the state. The most extensive deposits, and is here very extensive; is about six feet in thickness, and those alone which it may be safe to assert will yield a in quality is equal to the best gypsum of Nova Scotia. rich profit, are at the county seat of Kalamazoo, near The same mineral is found elsewhere in our state, but Concord, in Jackson county, in the county of Oakland, this is by far the most important locality at present and perhaps Wayne. No furnaces, for the reduction of known, and one that affords every facility for quarrying these ores, have yet been erected. It is shown, by the and distributing the mineral over the state. A mill was late census, that there are 15 furnaces in the state for erected during the past summer, and the ground plaster, the casting of pig iron, requiring 614 tons, and the whole for manure, is already manufactured in considerable amount of iron imported, under various forms, is much quantities. greater. The cost of this importation, which in so heavy Though the above locality is the only one known at an article as iron, is very considerable, might, and ought which gypsum occurs, in the interior of our state, yet, to be, saved to the state, by a domestic manufacture from the ascertained geological character and dip of our from our own material. For more detailed observations, rocks, and the associations of this mineral, it may be and an account of the localities at which this ore occurs, presumed that gypsum and its associated marls, will be see geological report of 1840, pages 28, 60 and 100. hereafter disclosed at other points in the vicinity of the BITUMINOUS COAL will be found in abundance for all the above bed, and that it will be found also to occur at other wants of the state. The only locality where mining localities, in the interior, which are concealed from operations have been commenced is at Corunna, present observation. Shiawassee county, where this mineral has been SHELL MARL occurs in the greatest abundance already used to considerable extent, and, though in the throughout the state, but more especially among the midst of a heavily timbered country, is for many marshes and lakes of the openings. It forms deposits, purposes preferred to wood or other combustible. Other varying in extent from 1 acre to 100, and these are pretty points also, eligibly situated for the mining of coal, have widely distributed. Its exceeding great value and been made known in Ingham, Eaton and Jackson cheapness, as a manure, is far from being truly counties, and it may be fairly inferred, from the facts appreciated by our citizens. But the time is rapidly already determined of the range of coal bearing rocks, approaching when this invaluable mineral will be no that outcrops of the coal beds will be found at numerous longer despised because it is abundant, simple and other points than those now known in these counties, cheap, and our state will then find, in her numerous marl and that coal will also be discovered in several counties beds, one of the richest treasures of which she is where it is not now known to exist, as through parts of possessed. For a full account of the nature and uses of Kent, Ionia and Genesee counties. (See further this mineral, the reader is referred to page 94 of the statements under pages 562 and 563 of present report.) report of 1840, and to previous reports. SALT. There no longer exists any doubt that this mineral The character, applications, and value of the rocks with may be obtained at a cheap rate and in any required which the above mentioned minerals are associated, quantity, for supplying the great and increasing demand together with other matters of practical interest, in our state. The operations commenced at the state connected with the geological structure of our state, are salt wells near Grand Rapids, Kent county, and on the so fully detailed in the preceding pages and in previous Tittabawassee, Midland county, are not sufficiently reports, that further allusion to them, in this place, is advanced to determine the extent of the anticipated deemed unnecessary. profit of the manufacture. The strongest brine obtained, up to this time, at the salt well of Mr. Lyon, at Grand From the foregoing facts, it cannot fail to be seen that, Rapids, will, without doubt, prove as productive as that while the soils of our state are admirably adapted to the of the best wells of Ohio and Virginia. So that the various purposes of agriculture, and for the production of present results may be considered as certainly indicative wheat—the most important product of the soil—superior of the success that was formerly supposed would attend to those of any known portion of the union, Michigan the boring for salt, if properly conducted, within our state. possesses, also, within herself, all the mineral treasures that are really requisite for sustaining and renovating her Michigan imports salt, probably to the amount of soil, for supplying the wants of her homesteads, and for $300,000 annually, which large amount of money might, maintaining those branches of domestic industry which as it soon will, be saved to the state, by the supplies are of the most importance to her people. Thus science furnished from her own resources. The average price of discloses those treasures, buried in the earth, which art salt, at the ports of entry, has been about three dollars and industry may appropriate to increase the profits of per barrel for the last four years. But when the works Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 46 of 59 labor. And though the objects of science are general in their nature, and not confined by the limits of districts or Report of S. W. Higgins, Topographer of states, the legislator feels a peculiar interest in having Geological Survey. those resources developed by its aid, which may be Detroit, January 24, 1841. turned to the advantage of his rising commonwealth; commerce, agriculture and the arts receive a stimulus by To DOUGLASS HOUGHTON, State Geologist: the new sources of wealth and supply which it opens to SIR—In fulfillment of your instructions, I have, in the the wants of each. In this view, the study of geology becomes one of the most universally useful that can present report, brought together such observations occupy the attention of practical men. relating to the magnetic variation in this state, as will, I trust, assist hereafter in affixing data to important facts. In comparing the extent of our resources thus obtained, Further developments will require a prolonged period with the little that was known concerning them a few and additional observations. But the readiness with years ago, we have reason to feel satisfied with the which the direction of magnetic lines may be prospect of future wealth and importance, which it has ascertained, by the help of the solar compass, will opened to us. If during the stirring times of an early render the labor and hazard of error a thousand fold less settlement, so rapid as has been that of our state, for the than any former method, and it is hoped that this past five years, less interest was excited by the compass will supercede everywhere, the necessity of development of our mineral resources than their depending alone upon the needle. importance might demand, a satisfactory cause may be found in the imperfect state of the knowledge hitherto A great desideratum is obtained in having an instrument obtained, and in the pressure of the more immediate that will decide between antagonist forces, and indicate the inflections of magnetic lines, and determine wants of a new, somewhat fluctuating and unsettled community. During the period mentioned, however, the mathematically, their amount. population of southern Michigan has advanced, from a From what has been advanced, an opinion is drawn in less number, probably, than 60,000 to 212,000; a rate of favor of magnetism being diffused throughout the increase unexampled even in the annals of a series of particles which compose the mass of the earth, and settlements, to the progress of which the world affords against that of a magnetic nucleus at its centre. The no parallel. Meanwhile, the liberal course of our state modifications in the magnetic lines on the peninsula, are policy has been steadily unfolding her resources, and, at seen to be abrupt and irregular, where there are no this moment, notwithstanding the burden of a heavy indications of ferruginous matter, and in the absence of debt, and the accumulated pressure of more widely felt mountainous chains, equally as where mountains do financial difficulties, we are rapidly advancing in wealth, exist. and are becoming awakened to the means of which we find ourselves possessed, for successfully competing But this subject when considered in connection with with older states, in the departments of agriculture, others, assumes no less importance. The changes commerce and manufactures. With lands among the which are silently and gradually progressing in the richest in the world, well watered and advantageously arrangement of the materials of the earth, are partly due situated for market, with water power abundant, and with to magnetic and electro-magnetic powers; other powers an extent of coast and facilities for water transportation may co-operate in the production of general results, but unequalled by any other inland state, and added to this, the first are known to be active where there are metals a population possessing a large share of that character and ores, and to these may probably be referred the for enterprise which distinguishes their countrymen, arrangement and filling of mineral veins. nothing will tend more to give full efficacy and In an economical point of view, the level tracts and permanency to these advantages, than to make more marshes in our state may be considered of great perfectly known the value of our mineral resources. Our importance. Though the expense of clearing new lands state is now sufficiently advanced to be able to avail is trifling, particularly our openings and plains, compared herself, properly and with certainty, of the advantages with the heavy timbered lands of the east, yet to drain alluded to, and there is every reason to believe, that the marshes and convert them into arable land, is still these will not longer fail to command attention, and that less expensive than either. There is little doubt of the the results will equal the most sanguine anticipations. success of operations in progress, by which many of BELA HUBBARD, them are becoming permanently dry, while others will Assistant Geologist require artificial aid. In either case large and valuable portions of the richest soil are reclaimed. There appears to be throughout the state, a singular connection between the marshes and the openings and plains; where the one is found the other is usually associated with it, while the timbered lands are comparatively free from either large or numerous marshes. The course of policy for the preservation of the timber on the openings, which must inevitably in time Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 47 of 59 become lessened in quantity, while its value increases, said that the needle is wholly indeterminate in their is to adopt those modes which will most speedily recover neighborhood in respect to them, “since the tracts under consideration, and thus prevent the *Professor Farrer. waste of timber which cannot be replaced. In the report which follows, and in which I have alluded the resultant of magnetic forces being then vertical,” or to the above subject with others, I did not feel at liberty nearly so, or nothing, “the horizontal element would be to extend my remarks further than a detail of facts. nothing.” If it is true, as has already been abundantly proved, that VARIATION OF THE MAGNETIC NEEDLE.—General law magnetism, electricity, and gravitation are governed by relating to magnetism—causes of the pertubations of the the same laws, and that they decrease in the ratio of the needle—experiment—opinion concerning local squares of their distances from attracting bodies, it attraction—mile applicable in explanation of the needle’s becomes difficult to define what is meant by “local attraction on the peninsula—general correctness of the attraction,” in the common acceptation of the term, observation in the public surveys-example—conditions unless it be granted that the regions where it has been by which it is demonstrated—description of the line of no met with so commonly, abound in ores, or metallic variation—its course independent—no correspondence substances to a great extent, or that it has been the in exterior lines-—similar system of curves at Great and misfortune of the surveyor to come so nearly in contact Little point aux Sable—BURT’S SOLAR COMPASS— with mineral masses, above or near the surface of the Professor Loomis’ report on annual changes in magnetic earth, as to occasion the utter temporary loss of the meridians—diffusion of magnetism, &c. polarity of the needle. The general law regulating the forces of magnetism, with It may be laid down as a rule, applicable hereafter in its direction and intensity, has been untiringly studied, explanation of most of the deviations of the needle, until by certain tests, it has at last been discovered that which occur in the central and western portions of the palpable effects are produced by the magnet on all state, (there being but few rocks in situ that appear on substances whether organic or inorganic, and there the surface, and those lime, slate and sand rock, and the seem to be only two ways of accounting for the geological structure of the peninsula, being such as to phenomena: “either that all substances in nature are preclude all opinion of there being ores or metals, or any susceptible of magnetism, or all possess particles of iron kind of minerals, except bituminous coal, marl, and the or some other magnetic metal, from which this property like, further than what is found in all alluvial and is derived.” mountainless countries, and there being an utter impossibility of any masses other than what may be The obvious pertubations of the needle, as seen in all erratic, capable of producing any great effect;) that as situations at times, arise from many small causes the direction of the needle is the effect of a principal combined, and which, so far as they exert their force, terrestrial force, its deviations arise only from those influence the greater power of terrestrial magnetism, smaller secondary forces which we have said are whereby it becomes proportionably feeble, as these inherent in all substances. combinations are multiplied. Atmospheric changes operate still further, and in a more sudden manner, to Many facts might be adduced in verification of the above effect the needle; but the first causes mentioned are the supposition, from the thousands of observations which most perplexing, and surveyors have attributed to local have been made during the course of the surveys of the causes that which is found to be inherent in all public lands in the state. Entire lines have been substances. measured from the southern to the northern boundary of the peninsula across its whole breadth on true The following single experiment will evince how far local meridians, and these lines have again been intersected causes are concerned in general. If a small needle be by others running east and west, at right angles, each constructed of any substance, and suspended between line having the magnetic variation recorded at intervals two magnets, it will be found to fie itself in a line in the of every six miles, the points of intersection. Within the direction of the poles of the magnets, and the number of limits of these lines is included the whole area of the oscillations in a given time, will usually determine in lower peninsula of Michigan, (and by an exact different needles, the quantity of matter susceptible of enumeration of the meanders of the coast, in the magnetism in each; thus an important discovery has intervals between the terminations of these lines, is been made by means of this active principle, whereby is obtained with the greatest accuracy, the number of detected the least insensible traces of iron, when all square miles it contains;) now from the collected other tests have failed.* observations, after rejecting those east of the principal The opinion then, is an erroneous one, that mineral must meridian, mentioned in my report of last year as always be present in masses, to cause the aberrations erroneous-—and a few others that might be specified of the needle. This is not necessary, nor is it the fact; for which are made to correspond to the measurement of those minerals which are deeply buried can have no fractional lines—an area of 41,304 square miles, is laid influence, inasmuch as their influence decreases out with the accuracy of a map, and the magnetic inversely as the squares of the distance, and it may be meridians traced with the same facility as any other Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 48 of 59 known and prominent feature; in fact we have a being in a lake, on the south-west corner of township 42 magnetic chart, indicating the declination of the needle, north, range 3 east; thence again the curve is reversed, over this extensive region, on parallels of equal whose radius is 2½ miles, crossing the south boundary distances of six miles. of the same township, 1¾ miles from its western boundary; whence the curve is again reversed, with a Let us pause here a moment to satisfy the inquirer, who radius of 2¾ miles, passing off the coast into Lake Huron may have doubted even the ordinary correctness of the again, passing over one of the small islands near observations, generally, obtained by the men whose Massacre island; thence ascending, it re-crosses the duty it has been to establish the standard and other south boundary of township 41 north, in range 2 east, exterior lines in the survey of our state. To this end the between sections 33 and 34; thence curving north- two examples mentioned in another part of this report, westerly, with a radius of 6½ miles, it crosses the town will be sufficient, though as I have stated, others might, line between ranges one and two east, 1¾ miles from with equal propriety, be adduced. One of the examples south boundary; still slightly curving northwardly, on a consists of forty-nine townships, and the other of fifty course of 12 miles, it crosses north boundary line of townships. township 43, range one east; thence two miles it These examples are all verified by actual measurement, intersects Monusco bay, and curving westerly, leaves and, as it was to be expected, one of them falls a little the water, and crosses the south-east corner of town 45, short, and the other has an excess, only of five links in a range one east, three-fourths of a mile from corner post, mile, above the convergence which all meridian lines into town 45, range 2 east; thence curving with, a radius have when run north. Now, if an error, the gross of of 6⅓ miles, enters,’ at the mouth of the Miscota Sawgee which should amount to 15’, had been made in their river, the Canoe channel of the straits of Ste Marie, and observations, the result would be a departure from crosses it about one mile above the Nebish rapids in that parallelism in the lines, of thirty-five links to a mile, channel, touching the most westerly point of Great whereas, the result exhibits an error of less than 2’ to a Sailor’s Encampment island, and keeping the western mile. and northern shore, with a curve whose radius is 8 miles; here its course is again reversed, and beyond this Now, it is obvious from the foregoing, that there must be we have no sufficient data to pursue it farther. one of two conditions, which has given precision to the examples we have adduced; either the magnetic It is believed, however, to pass directly on to the south- parallels have become greatly diminished in intensity, west point of Sugar island, keeping along its westerly and accommodated themselves to the plane of side, and crossing again the straits of Ste Marie on to astronomical longitude, or care and skill have been the main land, at the forks of the Montreal channel and exercised to modify the effects produced by them. Great Hay lake, five miles east of the Saut de Ste Marie; thence irregularly over the granite formations, and in The latter condition is the true one, as we shall shortly conformity to the littoral features of Goulais and demonstrate. We begin, then, at a point where the line Batcheewauanung bays, touching Michipicoten harbor; of no variation passes out of Lake Huron, and first thence, leaving the eastern end of Lake Superior, it has touches the south side of Drummond island. This island been said that it becomes forked, taking the is one of the north-westernmost of the chain of the circumference of Hudson’s bay, or that the variation is Manitous which divide the waters of the straits of Ste the same on the eastern and western sides of the bay. Marie. It first touches the island near the meander post on the shore, between ranges 7 and 8 east, in township We have now followed it from Drummond to Sugar 41 north, and is the tangent point to a curve of 4½ miles island, through its actual and determined course, leaving radius which it then makes on the island, the western nothing to conjecture; and we remark, that for that extremity of the curve touching again the south shore of distance, it is as well determined as any other the island in the middle of the next township, in range 6 ascertained line.* east; whence a reversed curve of 81 miles radius, This line, before touching Drummond island, where we approaches closely to the corners and one-fifth of a mile first commenced with it, may with almost equal certainty south of fractional township 41 and 42, ranges 5 and 6 be traced down along its southern course in, and to the east; thence on a course south 85° west, 6 miles, foot of Lake Hu- intersecting township line 41 between ranges 4 and 5, near the meander post south shore of the island; which *The hour should be noted as 10 o’clock, A. M., for observations on is another tangent point, to a curve, whose radius is 31 this line. miles. Along this curve, at the distance of one mile, is ron; although, for the reason that it is confined to the the western end of the island, and at the meander post lake, we may not always ascertain its distance from the for fractional township 41 and 42, range 4 east; thence shore. crossing the channel to the opposite side nearly, the curve terminates between Round island and the main The course it would now take, in the diminished part of land of the upper peninsula, one-fourth of a mile from the the lake, approaching the straits of Mackinac, would be shore; thence another reverse curve of 21 miles radius, somewhat analagous, it is presumed, to that in the just sweeps along the edge of the shore, northward of straits of Ste Marie. This fact is proved from Pointe de Tour, the western termination of the curve observation, first on the island of Mackinac, on the west, Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 49 of 59 and along the north-east and east shore of the nautical phrase, for at these points, the increase of peninsula, south of and opposite Drummond island. It variation amounts to 3° in thirty miles, exceeding 6° at makes a large curve, which approaches the end of the the points, while the increase is but 1° for the whole lake, without touching Mackinac, and receding from it, breath of Lake Michigan; the variation being but 7° in descends south-easterly to the termination on the coast, Wisconsin, on the opposite shore. of the town line between ranges four and five east, in The instrument used in ascertaining the particulars we town thirty-six north, where the variation is 1° 55’ east. have been stating, is one totally different in its principles The same variation is found at the termination of town and construction from the common compass, and is not line thirty-four north, ranges six and seven east; thence even dependent for its accuracy on the needle. It was east, eight miles, at Presque Isle, it is imperceptible. On invented by Judge Burt, of Macomb county; and the Thunder bay point, it is 45’ east, the line of no variation Messrs. Burts have given me the results of observations passing between the light-house on the outermost made by them with this instrument, during most of the Thunder bay island, four miles from the shore, and this last summer. The needle is used with this compass only point; its course thence is to the outlet of the lake, near when the sun is obscured by clouds; when the sun Fort Gratiot, where it crosses into Upper Canada. shines, the needle is screwed fast, and the time then From the fact that the line of no variation passing consumed in obtaining the true meridian, is not longer through a part of our state, we are in some measure than that ordinarily taken by a needle to settle, while it is better able to determine the rationale of another system infinitely more correct. of curves found elsewhere on the peninsula, particularly I had intended to have given a description of this on its western side, at the Great and Little Pointe aux valuable invention, but to do this clearly, without an Sable, where a greater intensity is observable on accompanying drawing, was found impracticable. It is approaching Lake Michigan from the east. called the “SOLAR COMPASS,” and consists chiefly of three Under the ordinary ideas of magnetism, it would not arcs, one of which is graduated to the ecliptic, the other have been believed that a line so curved as we have to the complement of latitude, and the third to the sun’s described, could have existed, without ascribing its declination, whereby, if the latitude be known, the others irregularity to some corresponding cause of local force. are known, viz: the sun’s declination, and the apparent time, and consequently the magnetic variation; or if the Although the upper peninsula of Michigan differs from sun’s declination only be known, then the latitude, and the lower, in regard to its geological features, the the others are known; or if the time be known, the others conclusion might be drawn that at the line of junction of can be ascertained by an almost instant adjustment. the rocks of the Riviere Ste Marie, as described in your third annual report, where it is well defined as at, and We have not only now been enabled to adduce facts through the outlet of the lake, the magnetic lines would confirmatory of the general principles of terrestrial be deflected, somewhat with the line of bearing of these magnetism, but to enter considerably into detail on the rocks, in a distance of thirty miles; but its course on the subject of magnetic variation. A variety of reasons contrary appears to be independent of them, crossing seemed to require this, the principle of which was, the them at right angles, and without regard to their definite course obtained of the line of no variation, and character. the consequent illustration of other lines on either side of it being also irregular; demonstrating a system of curves, Another peculiarity is, that corresponding curves, and a series of distinct and separate centres of exterior to the line of no variation, on either side, bear no attraction. This has been effected over no very limited comparison. At the head of Great Sailor’s encampment space, and is free from all that might be considered island, at the distance of two miles west, the variation is empirical. 1° 10’ east; and opposite the middle of the same island, at one mile east of the line, it is 40’ west; at five miles, 1° It is believed that in accuracy and fullness of detail, west, and at six miles 1° 10’ west; one mile south of these observations exceed all that has been hitherto Monusco bay, the distance of one and quarter miles east attained, nor am I aware that the line of no variation was of it, the variation is 1° west; five miles west, 2° 35’ east ever before traced continuously for any great distance, only, and the curve mentioned as again entering the lake or that other observations have been taken, than at between towns two and three, as well as the curve which those points where it has been crossed by the surveyor passes around the edge of the shore above Pointe de or mariner. Tour, have no variation at their centres, but on It has been pretty well determined by professor Loomis, approaching either way, east or west, variation increases of Western Reserve college, Ohio, that the “present to 30’, and then again decreases to 0, on touching the annual changes of variation, caused by the retrograde line of the curve. motion of the needle, which commenced everywhere as The same peculiarities are observed on the western side early as 1819, and in some places as early as 1793; is of the lower peninsula, particularly at Great and Little about 2’ for the southern states, 4’ for the middle and Pointe aux Sable, where the intensity increases, and the western states, and 6’ for the New England states.” This curves, though larger, exhibit as little conformity. It is is true in general of the magnetic lines in this state where evident that the needle “hauls to the land,” to use a they are at a distance from the line of no variation, as at

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 50 of 59 Detroit. Here the decrease or amount of retrograde Note.—July 19, at 12 h. 30 min. P. M., variation 1° 10’; at motion is 4 4-10’ annually; the line of no variation has 12 h. 45 min., var. 1° 15’; at 1 h., var. 1° 28’. July 24, at been quite stationary, at least for the last eight years, at 6 h. 10 min. P. M.? shower commences, var. 1° 85’; at 6 points where it was known at that period. While, h. 40 min., shower past, var. 1° 25’. July 27, at 5 h. 45 therefore, we observe a greater intensity, as we min. P. M., shower rising, var. 1° 47’; shower past, var. approach nearer to the line of no variation, we likewise 1° 37’. observe the distance to increase between the lines of equal variation, and while the first is stationary the latter COUNTY SURVEYORS—law respecting them—Judge is retrograding. Burt’s compass—magnetic meridians—disappearance of While the parallelism which takes place in needles, original lines. proves that the magnetic force of the terrestrial globe From the statute* regulating the duties of county may, like that of gravitation, act in parallel lines, we see surveyors, it becomes indispensible to possess also an exception. The lines of gravitation are always themselves of one of Burt’s solar compasses; for it is perpendicular to the surface of the sphere, while the made their duty to be acquainted, before entering upon a lines of magnetism, which like gravitation, never cross survey, with the absolute variation of the needle, at the each other, are composed of every variety of curve. time and place where the survey is to be made, and to Though the diffusion of magnetism be general, it is by no note the same upon their certificates, and no returns are means equal. It is found at the equator and at the poles, either lawful or can be received as evidence in any court, an interposed space equal to the earth’s radii, and for without it. It may be supposed that this might be this space no loss is apparently felt in its force, and it is dispensed with, when it is known that the surveyor in the not more difficult to conceive an exerting force through sub-division of a section, must be governed by the this, or a greater interposed space, than that the hand section and quarter section posts already established, should communicate motion to a stone, with which it is and that the business of dividing a section, therefore, is demonstrably not in contact. merely intersecting these posts with his line, without the power to change them when wrong; and when smaller If then magnetism be a real power, at what distance divisions are required, of taking equal distances between does it terminate? can we give it an inferior level, and them, whether the full complement of acres be wanting determine its final bounds, connected with solar light and or otherwise. heat? does it not emanate from, and is it not governed by that great central source, the sun, which controls the But though most surveyors have a meridian line for their more palpable and grosser materials of which the own accommodation, generally in their immediate planetary system is composed, which effects every neighborhood, from which they can determine the change either in the interior or exterior of this globe, and magnetic changes, yet when their duties require them in to which every element is subject, and by which are opposite parts of a county, where the variation not conducted in silent processes, all changes and unfrequently differs a degree, it is obvious that time must revolutions, since time began? be devoted to an observation of some star to obtain the variation, if it be a clear night, or if otherwise, the survey DIURNAL VARIATION. must be suspended until a more favorable time. Besides The following table of diurnal variation was sent to me by all this, his pay is fixed at a stated price per mile, and Hon. William A. Burt, who is in the constant practice of that price barely a compensation. Now, either to make keeping a meteorological table in connection with his the business desirable, and at the same time to fulfill the observations on the magnetic variation; the results are conditions of the law, he must have a ready method of the same as noticed in my former report, though not then getting the variation, or must spend his time in so doing, in detail. These observations were made in lat. 42° 43’, without an equivalent for his labor; and while the law N., long. 5° 24’ 30” west, from Washington. remains as it is, no instrument besides the solar compass can enable the surveyor, with profit, completely to fulfill the intent of the statute. This question is of no less importance now, than it will be

*Part first, title second, chapter third, section sixty-nine, revised statutes. In all surveys made as aforesaid, the course shall be stated according to the true meridian, and the variations of the magnetic meridian shall also be stated, with the day, month and year. Sec. 70. The surveyor and his deputies may demand and receive for their services, the following fees, to wit: for each mile actually run with the compass, and measured with the chain, three dollars: Provided, That the necessary chainmen and markers be furnished by the surveyors or his deputy, at the request of the parties requiring the survey, but if the chainmen and markers are furnished by the party for whom the survey is made, or if the chainmen and markers be not necessary, then the surveyor and his deputies shall receive for each mile run, seventy-five cents, &c.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 51 of 59 in future, when all traces of the original lines shall have In bodies of water like these lakes, slight changes in the been lost, which is the case already, wherever the seasons produce visible effects, in as much as they county has become settled and roads or fields have have no equalizing under-currents. been opened along the boundaries of section lines. The quantity of rain must have been much less, and the evaporation more, than for many years past, to have AREA OF THE LOWER PENINSULA OF MICHIGAN—former produced the decrease mentioned below. This decrease maps and descriptions, erroneous—definite information amounts in the first year to one quarter of the total rise, now obtained. and in the second to one half, making the proportion We have now the means of ascertaining, with the utmost each year as thirty-three to forty-four nearly. degree of accuracy, the precise area of the lower The maximum of August, 1838, was five feet three peninsula, an accuracy characteristic of the plan inches above that of 1819; that of 1889, three feet pursued where the general government has the control eleven inches; and that of 1840, two feet seven and one- of the surveys. These surveys afford the greatest facility half inches. The ratio of decrease, therefore, between in determining the boundaries and extent of every the highest water in 1838 and 1839, is one foot four portion over which they have been made, from an eighty inches; and between the highest water in 1839 and acre lot to a whole territory; and such has been their 1840, one foot three and one-half inches. progress within the last three years, that there remains only the small fraction of thirty-six townships Its rate of decrease is much more rapid than that of its unsubdivided; but these being mostly in the interior, increase from 1819 to 1838. In 1830 it was only two feet present no difficulty in determining at once the exact above the level of 1819; in 1836, three feet eight inches; number of square miles contained within the boundaries having risen one foot eight inches in six years. In 1837, under consideration. I have with extreme care, it was four feet three inches; increase, seven inches; in multiplied together every fraction, and find the whole June, 1838, five feet; increase, nine inches; and, in amount to be 41,304 square miles or 26,434,560 square August of the same year, five feet three inches. Having acres. been nineteen years in attaining the maximum of five feet three inches, and only two years in reducing that In giving the above estimate, we cannot avoid the height one-half, or to the average year of 1833. Thus opportunity of confronting its results with the the rapidity of its decrease in two years, equals the compilations of draftsmen and geographers, who, in increase of five years. relation to the peninsula, have heretofore, in the main, copied such estimates as have fallen in their way, I have not been able to ascertain whether the decrease whether right or wrong. But little care has been of former years was thus sudden, or whether the period exercised, even by those who ought to have been better of the minimum, or lowest stage of water, continues for acquainted with the errors which have always any great length of time; it is quite probable, however, characterized not only the maps, but the descriptions of that it does, and that the overflowing of the lands caused the peninsula. It is to be hoped that the period of such by the maximum rise, is but temporary, and only for one errors is now past, and that while most existing year, whence immediately commencing its decrease, it publications become obsolete, they will be replaced by arrives very soon at its former standard, and remains correct ones; for it is not too much to say that now, not there with little variation. Indeed, this is the more only correct, but precise and definite information can be probable, from the example of the last three years, and obtained, and wherever a dependence shall be placed from the appearance of long and undisturbed processes upon former maps and descriptions, so far will their in the growth of trees and vegetation, with the formation numerous and universal mistakes be the means of of permanent channels in the interim, as well as the leading into important errors. security felt by those who have erected buildings and planted orchards formerly, upon those lands which were inundated. ELEVATION AND DEPRESSION OF THE WATER IN THE GREAT LAKES—the maximum for 1838, 1839, and 1840—lowest The diminution in a given quantity of water, exceeds by stages of water of longer continuance than the higher evaporation, all the supplies which it receives from rain, stages—-evaporation—semi-annual alternations—effect that is the average amount of falling water, is equal per of winds—the apparent tides fortuitous—reaction of the year to 33 inches; evaporation will reduce it to 44 inches, waters—table of elevation and depression for 1840. when fully exposed to the sun and air. One season of extreme drouth would, upon the expanse of these lakes, The last year is the second since the unusual elevation produce an extreme depression, while the contrary of the waters of the lakes; since which time there has would have the effect of producing a corresponding rise. been yearly a remarkable coincidence in the ratio of their It cannot be a matter of so much astonishment that such subsidence, the more unlocked for, when taken in expanded areas of water, subject to such influences, connection with the causes which tend to equalize the should be greatly effected; the wonder is, that they do amount of falling water, in the form of rain, snow, and not oftener present greater fluctuations than they do, the dew, with the constant action of evaporation. equal and almost unvarying stage at which we find them, is due to the uniformity of the seasons, and the

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 52 of 59 systematic order in which nature is conducted in all her mile wide into the lake, was observed the returning works. waters from the west, in wide undulations. The effect upon the smooth surface of the bay was a gentle The semi-annual alternations observable in summer and elevation, which arose to one foot or more for a period of winter, arise from other and well known causes. In fifteen minutes, then subsiding, again returned at equal summer, the supply is unchecked, and the consequence intervals of time, until the lake, after a lapse of a few is, an increase to the height of 30 inches, or thereabouts; hours, resumed its natural level. when in winter, these supplies are again checked, a consequent depression follows. Measurements to ascertain exactly these semi-annual fluctuations, have never been thought necessary. Besides, it is not uncommon for ice, in large bodies, to collect at the outlets of the lakes, and, for the time, prevent the usual discharge, and a lower stage of water, is the consequence, than otherwise would be. When this occurs in the chain of lakes, as it frequently does at the outlet of Lake Huron, in connection with a west wind, as in 1824 and 1831, it diminished the depth-of the Detroit river, opposite the city, to over ten feet, widening the beach more than twenty rods, and making it practicable, (except in the immediate channel,) to cross without MARSHES—their origin—once inhabited by the danger, on foot, from the American side, to Isle au Beavers—their enlargement and diminution—other Cochons or Hog Island; and a further proportional causes of their production—without timber-—their decrease took place in Lakes Erie and Ontario, while the uses—marl—peat—rich soil—cause of the subsidence pent-up water flowed back into Lakes Huron and of the water on them—instances of their becoming dry— Michigan. For these reasons, and the want of uniformity causes still in operation—irreclaimable marshes. in the temperature of the winter months, the minimum height is not to be depended upon. It is perhaps a matter of less difficulty than is generally supposed, to account for the existence of most of the Besides all this, the effect of winds sometimes acts in marshes that so abound in this and other portions of the favor, as well as against, the other irregularities. The west. We may consider them as level tracts, so geographical position of the lakes is such, as that, continuous often as to be but little broken for many allowing them to prevail from the same point, at the miles, and which expand, or become narrow as the base same time over them all, (which is, by no means, always of the hills and higher grounds, approach or recede; the case,) they produce a variety of results. A west wind while the latter seem to stand as distinct and sharply forces the water of Lake Erie into the Niagara river, at defined as islands, whose shores are fringed by a line of the same time, the waters from the foot of Lakes Huron timber, and whose foliage waves over the tall grass and Michigan are forced into the straits of Mackinac, and beneath, and which borders the very margin of this these again are met by the waters of Lake Superior, timbered belt, at times receding like deep indented bays, through the straits of Ste Marie. Hence the straits which and again projecting in detached islands, and peninsula connect Lakes Huron and Erie, have all the indications points, not unlike the meanders of an actual arm of the of a tide, though irregular as to time, as well as to the sea or lake, the level grassy surface being substituted amount of its elevation and depression, and it has often for their waters. both rose and fell in about the same proportion, and sometimes in the same period, as the lunar tides in Most of the marshes, however extensive, were once the those rivers which empty into the ocean. But whenever habitation of the beaver, and were nothing more than these tides take place, either in the lakes themselves or expanded and shallow lakes of water. The stream that in the straits connecting them, they are fortuitous, and is now found universally to flow through them, was are the results of accidental disorder, common anciently at a lower level, which is sufficiently indicated throughout the lake region. when the depth of vegetable mould is penetrated and the former surface exposed. This depth is found to vary Another feature may be observed of the lakes, different from one to many feet. in nothing from the ground swell of the ocean,—the reaction of the water—after having been pressed by the From the well known habits of the beaver, we may wind for a few days or hours in one direction. suppose their first labor was to raise a dam sufficiently high to protect them from attacks by land, and as the The most favorable points for noticing this rëaction, is at bottoms of the lakes became filled up by the decay of an inlet or bay; Lake Superior, which has the largest grass and roots, an additional elevation of the dam surface, presents the most marked traits. Here, while became necessary, and this gave a greater area to the the explorations by the geological corps were in lakes, which continuing to spread, the adjacent land progress, the past season, at the mouth of Grand whose relative level could be but little above the ordinary Marrais river, which empties into a bay one mile wide banks of the stream, was overflowed, leaving those and two miles long, having an outlet of a quarter of a Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 53 of 59 islands, bays, and peninsula points we have alluded to, of a man, they have now no other water upon them than to give an indescribable beauty to the landscape. the original stream, and that no longer spreading over the whole surface as formerly, but confined to its proper A process of enlargement or diminution of the marshes, channel. is constantly going on according as the original cause is either operating or has ceased; the latter is the case The causes which will ultimately have a tendency to within, and to a great extent around, the neighborhood of drain the great portion of them, is slow in its operations, permanent settlements. The beaver is nowhere to be but nevertheless, is sure. The operation may be found, excepting at the sources of Thunder bay river, expedited by artificial means; either, by straightening the and some other minor streams, on the lower peninsula; usual serpentine course of the streams, or by enlarging but Mr. Burt informs me that he found them within twelve their outlets, or which is the most effectual method, by miles of the coast north of Mackinac, in considerable removing the embankment, or beaver dam. These may numbers, where they had newly inundated the country to in almost all cases be found by examination, though they the depth of several feet. are in a measure concealed, from the long period. of their standing, and the materials of their construction, Another cause of the stoppage of the streams, is the having become overgrown and covered with rank grass falling of timber across them, which becomes and mould, accumulated through long periods of years. permanently fixed by the superincumbent pressure of the waters. The law of fluids-—the property of water to preserve its level—the natural and uniform effects when opportunity A long series of years, if not ages, must have elapsed to can be given for its operation, in level and sunken produce the filling up of these ponds by the decayed districts, will drain the superfluous waters from a higher vegetation, and the destruction of so large a body of to a lower level, leaving the surface dry. Thus, as I am timber as that which once covered the ground they informed, parts of the extensive meadows on the river occupy, little or no vestige of these forests remaining, road, in the southern towns of Shiawassee county, for even of a fossiliferous character. miles, have the last year produced for the first time, The benefit of these marshes to the country, consists not crops of wheat, which, under my own observation, three altogether in their picturesque and verdant appearance, years ago, were too wet to allow of crossing upon them; or in the rural charm with which nature clothes them, so and in the adjoining townships, in the northern parts of far from being practically useless, they, in a great Livingston county, small lakes have altogether measure have, to this day, been the pasture grounds of disappeared. On the farm of Gen. Van Fossen, two of the domestic herds, which otherwise could not have these lakes contained about three-quarters of an acre been supplied in the first settlement of the country. Their each, and were intended expressly for stock water for first use has been to sustain, by their spontaneous his cattle; these and several small marshes in the same crops, the dependent husbandman, placing him beyond county, have all since become fields. The marshes, in the care and labor of opening new fields for his supplies. these instances, were all drained by the natural decay of old dams, or the wearing effects of the waters, in Another value, which will hereafter be better known and deepening the channel, and thus returning to their appreciated, is derivable from the immense beds of marl, ancient level. so universally found in them; with its uses, as a cement and manure, thousands are already acquainted. It is Further instances might be noticed, occurring in several well known to be peculiarly adapted to our soil as a counties in the state. In Branch county, several former manure, and its quantity is inexhaustible. marshes have actually emerged from a depth of two feet below the surface of the water. In these cases, the Another characteristic production of the marshes, is the relative level has so changed within about seven years, peat with which they abound; this may in future be found as to be at present at a height of two feet above the useful as a fuel, and may supply the place of that article water. when other sources are exhausted. Here a second cause has been operating with the first, Nor need I here announce, what is so well known, (and and which has given a greater rapidity in producing the which results from the fact of the composition of the soil, effects we have mentioned, that is, the preservation from being made up wholly of decayed vegetation,) their fire of the crops of wild grass; for if this is allowed to fall surpassing richness, or that when, by artificial drains, or and decay, the continued accumulations formed by it, otherwise, they have been made arable, the experiment will have a tendency to alter and raise the level yearly, of planting and sowing for years, has attested them the and but a short period of time will be necessary to most valuable and enduring lands in the state. So much complete the process. is this the case, that their acquisition by those who understand them best, is more eagerly sought for than Trees of a deciduous growth can never be supposed the richest of the woodland. again to grow upon them, and hence they will always have the appearance that natural prairies present, with Numbers have yearly become dry, so as to be brought the advantages of a uniformly rich soil, which all natural under cultivation, which have heretofore been known prairies have not. They will likewise necessarily always only as wet meadows, and where their yielding oozy receive the wash of the higher grounds. muck could with difficulty be made to support the weight Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 54 of 59 Suggestions in relation to the cause of the late gradual Glossary, including the technical terms used in this decrease of the waters of the great lakes, in connection report. with the disappearance of these smaller lakes and drying Alluvial. The adjective of Alluvium. of the marshes, have been offered, attributing both to the changes in the seasons only, so that a recurrence of Alluvion or Alluvium. Recent deposits of earth, sand, circumstances hereafter that shall produce a rise similar gravel, mud, stones, peat, shell banks, shell marl, drift to the one of 1838, in the great lakes, will also, it has sand, &c, resulting from causes now in action. This term been supposed, produce a similar submergence of the is generally applied to those deposits in which water is marshes, and fill again the small lakes. But I apprehend the principal agent. there is no connection between the causes which have Alum rock. Rocks, which, by decomposition, form alum. acted on the one and those which have effected the other. It is true that the three thousand interior lakes, Amorphous. Bodies devoid of regular form. especially those of any considerable magnitude, have had their ebbs and flows in the same ratio and at the Amygdaloid. A trap rock which is porous and spongy, same time and from the same causes as the great lakes, with rounded cavities scattered through its mass. but it should be remembered that no new instances of Agates and simple minerals are often contained in these marshes being formed, have been discovered, but on cavities. the other hand, when the waters of the lakes were rising Anthracite. A species of mineral coal, hard, shining, for years, and were at their maximum, an equal black and devoid of bitumen. progressive subsidence was taking place in the waters of the marshes. Anticlinal. An anticlinal ridge or axis is where the strata along a line dip contrariwise, like the sides of the roof of The number of irreclaimable marshes is comparatively a house. few, and their areas are circumscribed to the dimensions of the lake which originates them, and to the basins Arenaceous. Sandy, which enclose them. In the first case the lake is central Argillaceous. Clayey. and cannot be approached; the vegetation which had taken root in their margin, has been so often re- Augite. A simple mineral of variable color, from black produced, as to contract the actual dimensions of large through green and gray to white. It is a constituent of lakes, and confine the remaining open space of water to many volcanic and trappean rocks, and is also found in a small extent. This is in consequence of a floating, some of the granitic rocks. buoyant covering, fixed by the fibres of roots, which, Avalanche. This term is usually applied to masses of ice having been first supported by and around the shore, and snow which have slidden from the summits or sides has, in deep water, no other support than what the of mountains. It is now applied to slides of earth and surface of the lake itself affords. Hence, where these clay. lakes become entirely covered over, as in Sanilac, Cheboygan and Presque Isle counties, and in some Basalt. One of the common trap rocks. It is composed other instances, to a greater or less extent, the weight of of augite and feldspar, is hard, compact, and dark green a man causes a depresssion and a wave-like and or black, and has often a regular collumnar form. The trembling-motion to some distance round. The surveyor, Palisades of the Hudson show the columnar aspect of who is often compelled to cross them, well knows the trap rocks. The giants’ causeway is cited as an example feelings of insecurity they create. It may not be said of of basaltic rocks, and the columnar structure is there them, as was said by some travellers from London, on very strikingly displayed. their journey to the north, who, on arriving at Bitumen. Mineral pitch, which is often seen to ooze from Dumfreshire, in Scotland, concluded, from the fossil coal when on fire. appearance of the mountains there, that the world was finished no farther, and returned quietly home. Bituminous Shale. A slaty rock, containing bitumen, and which occurs in the coal measures. These subterranean lakes are nothing less than immense reservoirs of water; their coolness and purity Blende. Sulphate of zinc. A common shining zinc ore. exceed those whose surfaces are exposed, and being Bluffs. High banks of earth or rock with a steep front. fed by springs also serve as fountains to streams that The term is generally applied to high banks forming the rise in distant places. boundaries of a river or river alluvions. S. W. HIGGINS, Bog Iron Ore, Ochre. A variety of ore of iron which has Topographer to Geological Survey. been deposited by water. Chiefly in low, wet ground. Botryoidal. Resembling a bunch of grapes in form.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 55 of 59 Boulders. Erratic group. Lost rocks. Rocks which have Conglomerate, Crag, or Puddingstone. Rocks been transported from a distance, and more or less composed of rounded masses, pebbles and gravel rounded by attrition or the action of the weather. They cemented together by a siliceous, calcareous, or lie upon the surface or loose in the soil, and generally argillaceous cement. differ from the underlying rock in the neighborhood. Cretaceous. Belonging to the chalk formation. Breccia. A rock composed of angular fragments Crop out and out crop. Terms employed by geologists cemented together by lime and other substances. and mining engineers, to express the emergence of Calc Sinter. A German term for depositions of limestone rock, in place, on the surface of the earth at the locality from springs, and waters which contain this mineral in where it is said to crop out. solution. Crystaline. An assemblage of imperfectly defined Calcareous Rocks. A term synonymous with limestone. crystals, like loaf sugar and common white marble. Calcareous Spar. Crystalized carbonate of lime. Delta. Alluvial land formed at the mouths of rivers. Carbon. The combustible element of coal. Denudation. A term used to express the bare state of the rocks over which currents of water have formerly Carbonates. Chemical compounds containing carbonic swept, and laid the rocks bare, or excavated them to acid, which is composed of oxygen and carbon. form valleys of denudation. Carbonic Acid. An acid gaseous compound, incapable Deoxydize. To separate oxygen from a body. of supporting combustion, and deleterious to animal life. It is common in caves and wells, and many incautious Detritus and Debris. Broken and removed portions of persons lose their lives in consequence of descending, rock which have been operated upon by waters or the without first ascertaining its presence by letting down a atmosphere; frequently transported by currents to great lighted candle. Man cannot live where a candle will not distances. burn freely. Dykes. A kind of vein intersecting the strata, and usually Carboniferous. Coal bearing rocks. This term has been filled with some unstratified igneous rock, such as applied to formations belonging to an ancient group of granite, trap or lava. These materials are supposed to secondary rocks which contain coal. The term is now have been injected in a melted state into great rents or used in a more enlarged sense, and may be applied to fissures in the rocks. any rocks containing coal. Diluvium and Diluvion. Deposits of bowlders, pebbles Chalybeate. Impregnated with iron. and gravel, which many geologists have supposed were produced by a diluvial wave or deluge sweeping over the Chert. A siliceous mineral, approaching to chalcedony, surface of the earth. flint and hornstone. It is usually found in limestone. Dip. Where strata are not horizontal, the direction in Chlorite. A soft green scaly mineral, slightly unctuous. which their planes sink or plunge, is called the direction Chloritic Slate. Slate containing chlorite. of the dip, and the angle of inclination, the angle of dip. Clinkstone. A slaty feldspathic or basaltic rock, which is Dolomite. A magnesian limestone belonging to the sonorous when struck. primary class. It is usually granular in its structure, and of a friable texture. Cleavage. The separation of the laminae of rocks and minerals in certain constant directions. They are not Dunes. Sands raised into hills and drifts by the wind. always parallel to the planes of stratification, but are Earth’s Crust. The superficial parts of our planet which often mistaken for them. are accessible to human observation. Coal formation. Coal measures. These terms are Embouchure. From the French, signifying mouth or considered synonymous, and refer to the great deposit entrance, (of a river.) of coal in the older secondary rocks, which has been called the “independent coal formation.” There are, Eocene. The strata deposited during the oldest of the however, deposits of carbonaceous matter in all the tertiary epochs, as, for example, the Paris basin. geological periods, and several of them might also be Estuaries. Inlets of sea into the land. The tides and called coal formations. fresh water streams mingle and flow into them. They Conformable. When strata are arranged parallel with include not only the portion of the sea adjacent to the each other, like the leaves of a book, they are said to be mouths of rivers, but extend to the limit of tide water on conformable. Other strata lying across the edges of these streams. these may be conformable among themselves, but Exuviae. In geology, fossil remains. unconformable to the first set of strata.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 56 of 59 Fault. A dislocation of strata, at which the layers on one Gypsum. A mineral, composed of sulphuric acid and side of a dyke or fissure have slid past the lime, and extensively used as a stimulant manure, and corresponding ones on the other. These dislocations for making stucco and plaster casts, &c. It is also called are often accompanied by a dyke. They vary from a few Plaster of Paris. lines to several hundred feet. Hornblende. A mineral of a dark green or black color, Feldspar. One of the simple minerals, and next to and which is a constituent part of greenstone. quartz, one of the most abundant in nature. Hornstone. A siliceous mineral, approaching to flint in its Ferruginous. Containing iron. character. Fluviatile. Belonging to a river. Hydrography. A science which considers the waters of the globe, principally as relates to navigation, tides, Formation. A group of rocks which were formed during a currents, soundings, charts of coasts, &c. particular period, or which are referred to a common origin. In situ, in place. In their original position where they were formed. Fossils. The remains of animals and plants found buried in the earth, or inclosed in rocks. Some of these are but Kidney Ironstone. A variety of ore of iron which receives slightly changed, others are petrified and the organic Its name from the somewhat kidney shaped masses in replaced by mineral matter; some have decayed and left which it occurs. It accompanies the rocks of the the impression of the bodies, while others have been carboniferous group. formed by mineral matter deposited in the cavities left by Laminae. The thin layers into which strata are divided, the decay of the organic body. These last are called but to which they are not always parallel. casts. The term petrifaction is applied to those cases, in which organic matter has been replaced by mineral Lacustrine. Belonging to a lake. Depositions formed in substances. The form and structure of the original body ancient as well as modern lakes, are called lacustrine both remain. In casts, the exterior form alone is deposits. preserved. Fossils are also called organic remains. Landslip. It is the removal of a portion of land down an Fosiliferous. Containing organic remains. inclined surface. It is in consequence of the presence of water beneath, which either washes away the support of Galena. An ore of lead composed of lead and sulphur. the superincumbent mass, or so saturates the material, Garnet. A simple mineral, which is usually red and that they become a slippery paste. crystalized. It is abundant in most primitive rocks. Line of bearing, is the direction of the intersection of the Gneiss. A stratified primary rock, composed of the same planes of the strata with the plane of the horizon. materials as granite, but the mica is distributed in parallel Linear survey. A plan of surveying adopted by the layers, which will give it a striped aspect. United States government, by which the public lands are Geode. Geodiferous. Geodes are small cavities in rock, divided into rectangles, by straight lines. generally lined with quartzose or calcareous crystals. Lignite. Wood naturally carbonized and converted into a Geology. A science which has for its object to kind of coal in the earth. investigate the structure of the earth, the materials of Littoral. Belonging to the shore. which it is composed, the manner in which these are arranged, with regard to each other; and it considers the Loam. A mixture of sand and clay. action of all natural causes in producing changes, such Magnetic Meridian. A great circle passing through or by as the effects of frost, rain, floods, tides, currents, winds, the magnetical poles of the earth; to which the compass earthquakes and volcanoes. needle, if not otherwise hindered, conforms itself. This Economical Geology refers to the applications of “line of no variation,” is not stationary, but shifts geological facts and observations to the useful purposes eastward or westward of the true meridian, during a term of civilized life. of years. Granite. An unstratified rock, composed generally of Mural Escarpment. A rocky cliff with a face nearly quartz, feldspar and mica, and it is usually associated vertical like a wall. with the oldest of the stratified rocks. Mammillary. A surface studded with smooth small Graywacke, Grauwacke. A group of strata in the segments of spheres like the swell of the breasts. transition rocks; but the term has been so indefinitely Mammoth. An extinct species of elephant. applied, that other names will probably be substituted. Greenstone. A trap rock composed of hornblende and feldspar. Grit. A coarse-grained sandstone.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 57 of 59 Marl. By this term an argillaceous carbonate of lime is variegated sandstone. The European, so called, lies in a usually implied. By custom, its signification is much geological position immediately above the coal more extended, and means mineral substances, which measures.” act as stimulating or fertilizing manures. There are clay Nodule. A rounded, irregular shaped lump or mass. marls, shell marls, and various others. Ochre. See bog iron. Marly Clay. Clay containing carbonate of lime. Old Red Sandstone. “A stratified rock, belonging to the Mastodon. A genus of extinct fossil animals allied to the carboniferous group of Europe.” elephant. They are so called from the form of the grinders, which have their surfaces covered with conical Oolite, oolitic. “A limestone, so named, because it is mammillary crests. composed of rounded particles, like the roe or eggs of fish. The name is also applied to a large group of strata, Matrix. The mineral mass in which a simple mineral is characterized by peculiar fossils,” imbeded, is called its matrix or gangue. Organic Remains. See Fossils. Mechanical origin, Rocks of. Rocks composed of sand, pebbles or fragments, are so called, to distinguish them Orthoceratite. The remains of an extinct genus of from those of a uniform crystaline texture, which are of molluscous animals, called Cephalopoda. The chemical origin. orthoceratites are long, straight, chambered shells. Metamorphic Rocks. Stratified division of primary rocks, Out-crop. See Crop out. such as gneiss, mica slate, hornblende slate, quartz Out-liers. Hills or ranges of rock strata, occurring at rock, &c, and which may probably be regarded as some distance from the general mass to the formations altered sedimentary rocks. to which they belong. Many of these have been caused Metalliferous. Containing metals or metallic ores. by denudation, having removed parts of the strata which once connected with outliers with the main mass of the Mica. A simple mineral, having a shining silvery surface, formation. and capable of being split into very thin elastic leaves or scales. The brilliant scales in granite and gneiss are Oxide. A combination of oxygen with another body. The mica. term is usually limited to such combinations as do not present active acid or alkaline properties. Micaceous. In part composed of scales of mica. Palaeontology. A science which treats of fossil remains. Mica Slate. One of the stratified rocks belonging to the primary class. It is generally fissile, and is characterized Peat. A product resulting from the accumulation of by being composed of mica and quartz, of which the vegetable substances, found in marshy places, in a former either predominates, or is disposed in layers, so partially decomposed and sometimes compact state. that its flat surfaces give it the appearance of Peat may be fibrous, ligneous, &c. predominating. Pisolite. A calcareous mineral, composed of rounded Miocene. One of the deposits of the tertiary epoch. It is concretions like peas. more recent than the eocene, and older than the Pliocene. The upper, or more recent tertiary strata. This pliocene. group of strata is divided into the older and newer Mollusca. Mollucous animals. “Animals such as shell pliocene rocks. fish, which, being devoid of bones, have soft bodies.” Petroleum. A liquid mineral pitch. It is common in the Mountain Limestone. “A series of limestone strata, of region of salt springs in the United States. which the geological position is immediately below the Porphyry. A term applied to every species of unstratified coal measures, and with which they also sometimes rock, in which detached crystals of feldspar are diffused alternate.” through a compact base other mineral composition. Muriate of Soda. Common salt. Productus. An extinct genus of fossil bivalve shells. Naphtha. A fluid, volatile, inflammable mineral, which is Plastic Clay. One of the beds of the Eocene period. common in volcanic districts, and in the vicinity of the The plastic clay formation is mostly composed of sands salt springs of the United States. with associate beds of clay. Native Metals. Those portions of metals found in nature Primary rocks. Those rocks which lie below all the in a metallic, or uncombined state, are called native. stratified rocks and exhibit no marks of sedimentary New Red Sandstone. “A series of sandy and origin. They contain no fossils, and are the oldest rocks argillaceous, and often calcareous strata, the prevailing known. Granite, hornblende, quartz and some slates color of which is brick-red, but containing portions which belong to this division. are greenish grey. These occur often in spots and Pudding Stone. See Conglomerate. stripes, so that the series has sometimes been called the

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 58 of 59 Pyrites. A mineral, composed of sulphur and iron. It is Stratum. A layer of rocks; one of the strata. usually of a brass yellow, brilliant, often crystalized, and Strike. The direction in which the edges of strata crop frequently mistaken for gold. out. It is synonymous with line of bearing. Quartz. A simple mineral, composed of silex. Rock Syenite and Sienite. A granitic rock, in which crystal is an example of this mineral. hornblende replaces the mica. Rock. All mineral beds, whether of sand, clay, or firmly Synclinal line and Synclinal axis. When the strata dip aggregated masses, are called rocks. downward, in opposite directions, like the sides of a Sandstone. A rock composed of aggregated grains of gutter. sand. Talus. In geology, a sloping heap of broken rocks and Schist. Slate. stones at the foot of many cliffs. Seams. “Thin layers which separate strata of greater Tertiary strata. “A series of sedimentary rocks, with magnitude.” characters which distinguish them from two other great series of strata—the secondary and primary—which lie Secondary Strata. “An extensive series of the stratified beneath them.” rocks, which compose the crust of the globe, with certain characters in common, which distinguish them from Testacea. “Molluscous animals, having a shelly another series below them, called primary, and another covering.” above them, called tertiary. Tepid. Warm. Sedimentary rocks. All those which have been formed Thermal. Hot. by their materials having been thrown down from a state of suspension or solution in water.” Thin out. Strata which diminish in thickness until they disappear, are said to thin out. Selenite. Crystalized gypsum. Topography. The description or delineation of the Septaria. Flattened balls of stone, which have been varieties of surface, and whatever else relates to the more or less cracked in different directions, and general exterior character of a country. cemented together by mineral matter which fills the fissures. Transition Rocks. A series of rocks which lie below the secondary and next above the primary, and are so called Serpentine. A rock composed principally of hydrated because they seem to have been formed at a period silicate of magnesia. It is generally an unstratified rock. when the earth was passing from an uninhabited to a Shale. An indurated clay, which is very fissile. habitable condition. They contain numbers of characteristic fossils. Shell Marl—Fresh water Shell Marl. A deposit of fresh water shells, which have disintegrated into a grey or Trap—Trappean Rocks. Ancient volcanic rocks, white pulverulent mass. composed of feldspar, hornblende and augite. Basalt, greenstone, amygdaloid and dolomite, are trap rocks. Shingle. The loose water-worn gravel and pebbles on shores and coast. Travertin. “A concretionary limestone, hard and semi- crystaline, deposited from the water of springs.” Silex. The name of one of the pure earths which is the base of flint quartz, and most sands and sandstones. Tufa Calcareous. “A porous rock, deposited by calcareous waters on exposure to air. and usually Silicious. Containing silex. containing portions of plants and other organic Silt. “The more comminuted sand, clay and earth, which substances incrusted with carbonate of lime.” is transported by running water.” Tufaceous. A texture of rock like that of tuff. Simple Minerals—Are composed of a single mineral Tuff or Tufa. “An Italian name for a volcanic rock of an substance. Rocks are generally aggregates of several earthy texture.” simple minerals cemented together. Unconformable. See conformable. Slate. A rock dividing into thin layers. Veins. Cracks and fissures in rocks filled with stony or Stalactite. Concreted carbonate of lime, hanging from metallic matter. Most of the ores are obtained from the roofs of caves, and like icicles in form. metallic veins. Stalagmites. Crusts and irregular shaped masses of Vein-stone. That mineral matter with which the ores or concreted carbonate of lime, formed on the floors of metallic contents of a vein are associated. caves, by deposits from the dripping of water. Zoophytes. Coral sponges and other aquatic animals Stratification. An arrangement of rocks in strata. allied to them. Strata. Layers of rock parallel to each other.

Annual Report of the State Geologist 1841 [Joint Doc. 11] – Page 59 of 59